Potato Diet Community Trial: Sign up Now, lol

In French, the word for potato is pomme de terre. This literally translates to apple of the earth. By this logic, potatoes are the lowest-hanging fruit of all.

More seriously: We keep getting more and more interested in the all-potato diet. This is a diet where you eat nothing but potatoes (and sometimes a bit of seasoning) for a few weeks to a few months. It sounds like a dumb gimmick that could never work, but there are a surprising number of people out there saying that they tried it, it worked for them, and they kept the weight off for months or even years after.

Anecdotes are limited in all sorts of ways, but there are a surprising number of very strong anecdotes about the all-potato diet causing huge amounts of easy, sustainable weight loss:

Again, anecdotes by themselves are limited. We don’t know how many people tried this diet and didn’t get such stunning weight loss. We don’t know how long the weight stays off for. And the sample size is really small. Someone should really do a study or something, and figure this thing out.

Well, ok, if you insist. But you all have to help! 

Tl;dr, we’re looking for people to volunteer to eat nothing but potatoes (and a small amount of oil & seasoning) for at least four weeks, and to share their data so we can do an analysis. You can sign up below.

Aren’t there already diets that work? Well, maybe, but we certainly don’t have any that work reliably. Reviews of meta-analyses say things like, “Numerous randomized trials comparing diets differing in macronutrient compositions (eg, low-carbohydrate, low-fat, Mediterranean) have demonstrated differences in weight loss and metabolic risk factors that are small (ie, a mean difference of <1 kg) and inconsistent.” And The Lancet says, “unlike other major causes of preventable death and disability, such as tobacco use, injuries, and infectious diseases, there are no exemplar populations in which the obesity epidemic has been reversed by public health measures.” We could go on like this all day — actually wait, we already did

There are all sorts of crazy fad diets out there that haven’t been formally tested, and many of them have anecdotes that sound at least this good. Some of you may have even tried one. So why are we so interested in this over all the others?

Most diets are unpleasant and require you to use a lot of willpower to eat the right stuff or avoid the wrong stuff. On most diets, people are hungry all the time and feel terrible and gain the weight back as soon as they stop dieting. But the potato diet, at least according to the anecdotes, isn’t unpleasant at all — it’s quite easy. This isn’t a willpower diet. If the diet works, and it’s as easy to stick to as they say, that would be an important finding.

Most diets are hard to follow in that the instructions are precise and/or complicated — you have to eat exactly the right ratio of stuff to other stuff, carefully weigh and measure all your portions, count calories, do a lot of math in your head, check all the ingredients in everything you buy, etc. In contrast, the all-potato diet is really simple. No complex principles. No weighing and measuring your food. No checking ingredients. Just potato.

Some diets claim they won’t work unless you do everything just right. If you don’t lose weight on one of these diets, fans of the diet can always fall back on saying, maybe you did it wrong. In comparison, potato diet is easy. We don’t think it really matters if you accidentally eat a chocolate bar, as long as you are eating mostly potatoes. If you eat mostly potatoes and you don’t lose weight, then the diet doesn’t work, no one will be saying “you did it wrong.”

The potato diet also appears to have a huge effect size — 20 lbs for Chris Voigt, 114 lbs for Andrew Taylor, etc. — which should make it easy to study. We’re not fiddling around with a diet that might make you lose 5 lbs. If most people lose as much weight as Chris and Andrew, that will be really obvious. And if it doesn’t work for most people, well, that’s an important finding too.

Finally, one of the most interesting things about the potato diet is that people seem to keep the weight off afterwards, which is basically unheard of for diets. If we can confirm that in a study, it will be a pretty big deal. 

So that’s why we want to study the potato diet in particular. It should be easy to get a straight answer about this diet. If it works, people will be able to use this diet to lose weight and gain energy, if that’s what they want. And if it works, it probably provides some kind of hint about why the obesity epidemic is happening in the first place. So let’s do a study.

Diet Design

To figure out how to run this study, we needed to figure out what kind of all-potato diet seems to work for weight loss. To do this, we took a close look at the case studies we mentioned above. Some of these accounts are pretty detailed, so we won’t bore you with it up front. If you want more detail, we give an overview of each case study in the appendices.

The overall picture looks pretty clear. The basis of the all-potato diet is, unsurprisingly, eating almost nothing but potatoes.

In the most extreme cases, like Penn Jillette and the Krocks, people appear to eat literally nothing but potatoes, with no seasonings, and drink nothing but water. This seems to work pretty well but sounds like it would be hard to stick to. It’s notable that both of these examples kept it up for only two weeks, though they did lose impressive amounts of weight.

In comparison, Andrew Taylor was able to stick to an all-potato diet for a full year. He let himself use spices and seasonings, drank things other than water, and he still lost more than 100 pounds. He just made sure to take a B12 vitamin and kept away from oil and dairy.

Chris Voigt lost the least weight, but he seems to have had a pretty easy time of it. He was able to lose 21 lbs while using all kinds of salt and seasonings and cooking his potatoes in oil, and he wasn’t even trying to lose weight at all. This suggests, to us at least, that stricter versions of the diet aren’t necessary to see the benefits.

Potatoes are indeed very nutritious (here’s the USDA page for russet potatoes). The official word is that they don’t contain any vitamin A and don’t contain any B12. We’re not sure about the vitamin A — Andrew Taylor went a year without supplementing vitamin A (he did take B12), but maybe he got all the vitamin A he needed from the sauces he used? In any case, a vitamin B12 supplement is appropriate, and a vitamin A supplement seems like a good idea. [EDIT: u/alraban on reddit points out that Andrew ate sweet potatoes, which are high in Vitamin A. This is a good point, so now our recommendation is that you should either include sweet potatoes or take a Vitamin A supplement.] If you take a normal multivitamin you should be totally covered — but again, none of the case studies seem to have needed it.

Based on these examples taken together, our version of the diet is: 

THE POTATO DIET

  • Drink mostly water. You can also have some other beverages. Chris Voigt had coffee, tea, and diet soda. Andrew Taylor sometimes had beer, even. Just don’t take them with cream or sugar and try not to get too many of your daily calories from your drinks. 
  • Eat potatoes. Buy organic if you can, and eat the peels whenever possible. Start with whole potatoes and cook them yourself when you can, but in a pinch you can eat potato chips or fries if you need to. You can calculate how many potatoes to eat (a potato is about 100 calories, so if you need 2000 kcal/day, eat about 20), but we think it’s better to eat the potatoes ad libitum — make a lot of potatoes and just eat as much as you want.
  • Perfect adherence isn’t necessary. If you can’t get potatoes, eat something else rather than go hungry, and pick up the potatoes again when you can. 
  • Seasonings are ok. Chris used seasonings like Tabasco sauce, chives fresh out of his garden, a Thai herb/pepper paste, and bouillon cubes in water for fake gravy. Andrew used seasonings like dried herbs, fat-free sweet chili, barbecue sauce, and soy milk (in mashed potatoes). Do what you can to keep yourself from getting bored.
  • Oil is ok. Chris used it, Andrew and Penn didn’t. You can go either way. In fact, it would be great for us if some of you use oil and others of you don’t, so we can see if there is any difference. If you do use oil, probably use olive oil, which seems to be what Chris used. Maybe consider imported olive oil from Europe, which we suspect contains fewer contaminants, in case the contamination theory is correct.
  • Take a daily B12 supplement, since potatoes don’t contain any. We like this version but use whatever you like. Take vitamin A if you’re not eating sweet potatoes. A multivitamin would also be fine as long as it contains B12. 
  • Everyone seems to agree: No dairy. Maybe this doesn’t matter, but on the off chance this is really important for some reason, please avoid all dairy products. 

If in doubt, pick one of the examples we describe in the appendices and follow their example. You can always ask yourself, what would Chris Voigt do? And then do that.

In the spirit of self-experimentation, and because we were curious, one of us decided to try the all-potato diet for ourselves. That author is currently on day 11 of the all-potato diet. In that author’s own words: 

I was originally going to do just one or two days of the potato diet to see what it was like, but it was so easy that I figured I should try to keep to it for a full week. But it was still easy at a week, and now I’m just curious how long I can keep going for.

I feel fine, totally normal. I don’t feel more energetic than normal, but I’m pretty energetic to begin with. My mood is a little better, and I’m maybe sleeping better. Exercise seems easier, or at least it’s not any harder, kind of surprising when all my protein comes from potatoes. I haven’t lost any weight but I’m not overweight so I didn’t have much to lose in the first place.

It doesn’t require any willpower. I don’t crave anything else, I’m not tempted to buy other food at the grocery store, I’m not jealous when people around me are eating pizza or chocolate. I’m happy to sit down to a pile of potatoes every meal. They still smell delicious. If anything, I like potatoes even more now. The hardest part is the logistics of preparing that many potatoes every single day. 

I’m using European olive oil, salt, spices, vinegar, and a couple of hot sauces to keep the potatoes interesting. I want to say that it would be much harder without them, but honestly, this is so much easier than I expected, I don’t know what to expect anymore. Maybe it would be just as easy without oil and hot sauce.

Here’s my advice based on my personal experience. You should get a wide variety of potatoes. When you’re eating nothing but potatoes, the differences between different varieties become very obvious. At first I was happy with yukon gold but after a few days I began to crave russet potatoes. Make a lot every time you cook, you will eat more than you expect. And make sure to drink lots of water, I keep finding it hard to remember and end up feeling dehydrated.

UPDATE DAY 13: For the last two days I tried nothing but baked potatoes with no oil and barely any spices. It was really easy, I feel super energetic, and I started losing weight. So if the diet isn’t having any effect for you, consider trying it with no oil.

Study Design

That’s the diet we’re thinking of. What about the study design? 

Official-sounding diet studies from like the NIH and stuff don’t always run all their subjects at the same time, so we won’t bother doing that either. We’ve made it so you can sign up and participate in this study at any time. Rolling admissions.

There’s no need for a control group because the spontaneous remission rate for obesity is so low. For example, if someone said they had invented a medicine that could re-grow lost limbs, we wouldn’t need a control group for that trial, because the spontaneous limb regrowth rate is almost exactly zero (in humans anyways). If anyone regrew their arms or legs, that would be pretty convincing evidence that the medicine works as promised. Similarly, people almost never spontaneously drop 20 pounds, so we don’t need a control group.

This is also a trap. We expect that some people will come back with “but there wasn’t a control group!” This is a sign that they didn’t actually read what we’ve written and are boneheads who don’t understand how research works.

We’re not worried about tight experimental control. Maybe this diet would work better in the lab, but what we are actually interested in is how it works when implemented by normal people in the comfort of their home. If it doesn’t work in those circumstances, we want to know that! If the potato diet can’t be used practically, we don’t really care if it works in the lab, we know which side our potato is buttered sprinkled with garlic salt on. If it doesn’t work with this design, it just doesn’t work. And if it does work at home, it would presumably work even better in the lab. 

We’re also interested in the huge effect size described in the anecdotes above. We’re not worried about tiny amounts of noise from things like what you’re wearing or what time of day you weigh yourself. If the experience of Chris Voigt is at all typical — if the average person loses about 20 lbs — these tiny differences won’t matter.

And we’re not all that worried about adherence. If the 100% potato diet works, the 90% potato diet probably works too. So while we prefer that anyone sending us their data tries to refrain from eating any delicious pickles during the diet, if you do eat a pickle, it probably doesn’t matter.

Sign up to Eat Potatoes for the Glory of Science

This looks pretty promising, so let’s try to go past the anecdotes and do this in something like a rigorous fashion. Who wants to eat some ‘taters? 

The only prerequisite for signing up is being willing to eat nothing but potatoes for at least four weeks, and being willing to share your weight data with us.

(And being an adult, having a scale, not being allergic to potatoes, etc. etc.)

One reason to sign up is that you hope this will help you lose weight, lower your blood pressure, make you less depressed, or see one of the other effects reported by people like Chris Voigt and Andrew Taylor. But another reason you might want to sign up is to help advance the state of nutritional science. In a small way, this study will tell us something about nutrition, weight loss, and obesity that we don’t currently know. If the diet works, it will give us a practical intervention that people can use to reduce their weight, which we don’t really have right now.

And beyond that, running a study like this through volunteers on the internet is a small step towards making science faster, smarter, and more democratic. Imagine a future where every time we’re like, “why is no one doing this?”, every time we’re like, “dietary scientists, what the hell?”, we get together and WE do it, and we get an answer. And if we get a half-answer, we iterate on the design and get closer and closer every time. 

That seems like a future worth dreaming of. If you sign up, you get us closer to that future. We hope that this is only the first of what will be a century full of community-run scientific trials on the internet. Maybe by 2030, the redditors will have found a way to triple your lifespan. But for the first study, let’s start with potato.

We understand that eating nothing but potatoes for four weeks sounds pretty daunting. But based on the case studies above, and our own experience, we want to reassure you that it will probably be much easier than you expect. In fact, here’s our suggestion: If you are at all interested in trying it, go ahead and sign up and start collecting your data. Try the first day or two and see how it feels.

If it’s really hard for you to stay on the diet and you just can’t continue, go ahead and stop, just send us an email and close out the diet as normal (see instructions below). We’re interested in the diet as a whole, and if 40% of people can’t stick to the diet for more than two days, that’s important information about how effective the diet is in a practical sense. We’d be happy to have that information. 

But based on our own experience, we suspect that most of you who try it for a couple days will be like, “wow this is so easy! I could do this for a couple weeks no problem.” If that’s how you feel, keep collecting your data and see if you can keep it up for four weeks. 

If you want to go for longer than four weeks, that’s great, we would be happy to have more data.

If at any point you get sick or begin having side-effects, stop the diet immediately. We can still use your data up to that point, and we don’t want anything to happen to you.

If you are taking potassium supplements, often given as blood pressure medications (like Losartan) please take this extra seriously. A diet of 20 potatoes a day will give you about 300% your recommended potassium. While this should be safe by itself, it might be a problem if you are already taking a potassium supplement. Don’t sign up if you have bad kidneys, kidney disease, or diabetes (you can check with your doctor). Be aware of the signs of hyperkalemia.

We are mostly interested in weight loss effects for people who are overweight (BMI 25+) or obese (BMI 30+), but the energy and mental health effects reported in some of the case studies are interesting too. If you are “normal weight” (BMI 20-25) you can also sign up, especially if you want to feel more energetic or you want to tackle depression and anxiety or something. 

And for everyone, please consult with your doctor before trying this or any other weight loss regimen. We are not doctors. We are 20 rats in a trenchcoat. eee! eee! eee!

Anyways, to sign up: 

  1. Fill out this google form, where you give us your basic demographics and contact info. You will assign yourself a subject number, which will keep your data anonymous in the future. [UPDATE: Signups are now closed, but we plan to do more potato diet studies in the future. If you’re interested in participating in a future potato diet study, you can give us your email at this link and we’ll let you know when we run the next study.]
  2. We will clone a version of this google sheet and share the clone with you. This will be your personal spreadsheet for recording your data over the course of the diet.
  3. On the first day, weigh yourself in the morning. If you’re a “morning pooper”, measure yourself “after your first void”; if not, don’t worry about it. We don’t care if you wear pajamas or what, just keep it consistent. Note down your weight and the other measures (mood, energy, etc.) on the google sheet. Then spend day 1 eating nothing but potatoes. On day 2, weigh yourself in the morning, note down data in the sheet, then spend day 2 eating nothing but potatoes. On day 3, etc.
  4. We prefer that you stick closely to the diet for at least four weeks. But if you do break the diet at some point, just note that down in the appropriate column and try to stick to the diet the next day. Again, we’re interested in how the diet works for normal people at home, and so imperfect adherence is ok. If you totally can’t stand the diet, just stop doing it and end the study per the next instructions.
  5. Whenever you are done with the diet (preferably four weeks, or longer if you want, we’re happy to have more data if you are enjoying the diet), weigh yourself and fill out one last morning’s data so we have an endpoint, then stop the diet.
  6. Then, send us an email with the subject line “[SUBJECT ID] Potato Diet Complete”. This will let us know to go grab your data. This is also your opportunity to tell us all about how the diet went for you. Please tell us all the data that doesn’t easily fit into the spreadsheet — how you felt on the diet, what brand of oil you used, what kind of potatoes you bought, where you got them from, what kind of cookware you used, before and after pictures (if you want), advice to other people trying the diet, etc. We think there’s a pretty good chance that this diet will work for some people and not for others, and if that happens, we will dig into these accounts to see if we can figure out why (e.g. maybe this works with olive oil but not with vegetable oil, or something).
  7. If we have our act together, we will send each of you a brief google form following up at 6 months and at 1 year, and maybe at future intervals (5 years?).

Assuming we get 20 or so people, we will write up our results and publish them on the blog. We would really like to get a couple hundred people, though, since at that point it becomes possible to do more complex statistical analyses. So if you think this is an interesting idea, please tell your friends. 

We’ll keep this updated with roughly how many people have signed up and stuff, until we get bored or decide the study is closed:

Signed Up: 220 [CLOSED]

Past the 4-Week Mark: 46

We’re pretty happy with this study design. In particular, we don’t think it’s a weakness that people are doing this at home, since those are the conditions that we actually want to understand the diet under. We want to know how it works when it’s applied like it would actually be applied.

That said, if you are a wealthy donor and you want to fund a more controlled version of this — maybe, send 30 overweight and obese volunteers to a campground in Colorado for a couple weeks and feed them nothing but potatoes while they’re there, and hire a nurse or two to check up on them every day — please contact us. It’d be cheap as far as nutrition research goes, and we’ll make you a mixtape of potato songs.

Appendix A: Super Basic Potato Preparation

Use whatever recipes you want, but here are two very simple ways to prepare them.

Here’s how to roast any kind of potato:

  1. Preheat oven to 425 F.
  2. Spread a thin layer of olive oil on a large cookie sheet.
  3. Wash potatoes and make sure they do not have any dirt or anything gross on them.
  4. Cut off any gross spots on the outside of the potatoes.
  5. Cut the potatoes into any of the following: large fries, slices about a quarter inch thick, or chunks a little bigger than a grape. Do the whole batch with the same method.
  6. If you find any other bad spots while you’re cutting up the potatoes, cut them off and throw them away.
  7. Put the cut potatoes in a large bowl and dress them with olive oil, salt, and whatever seasonings you want (salt, pepper, garlic powder, rosemary, etc.). Mix them so the oil and seasoning is all over the potatoes.
  8. Put the potatoes on the cookie sheet and make sure they are all well seasoned / well oiled.
  9. Put them in the oven for 20 minutes, then take them out and stir them with a wooden spoon or spatula. They will probably stick to the cookie sheet a bit, this is normal.
  10. Put them back in for another 20 minutes and then take them out again. Let one cool and try it, making sure not to burn your mouth. If it seems done and edible, turn off the oven, your potatoes are done. If it still seems a little raw, put them back in for another 10 minutes.
  11. When done, eat with your favorite no-calorie sauces and vinegars.

Here’s how to boil any kind of potato:

  1. Fill a pot with enough water to cover however many potatoes you’re making. Salt the water and set it on the stove on high to boil.
  2. Wash potatoes and make sure they do not have any dirt or anything gross on them.
  3. Cut off any gross spots on the outside of the potatoes.
  4. Cut the potatoes into small chunks. Any size is fine, but smaller chunks will cook faster.
  5. If you find any other bad spots while you’re cutting up the potatoes, cut them off and throw them away.
  6. When the water boils, put the potatoes in and turn the heat to medium.
  7. Every five minutes, pull out a potato chunk, let it cool, and taste it to see if it’s ready. 
  8. When they are done, turn off the heat and pour the potatoes out into a colander. 
  9. Dress the potatoes with spices and olive oil (you probably want to add salt) and eat with your favorite no-calorie sauces and vinegars.

Appendix B: Chris Voigt

The earliest example of an all-potato diet we’re aware of is a guy named Chris Voigt

Chris was the Executive Director of the Washington State Potatoes Commission, and he was tired of hearing all the myths about potatoes being unhealthy. He wanted to remind people about the amazing nutrients contained in this everyday vegetable. So as a demonstration of the power of potato, he decided to eat nothing but 20 potatoes a day, for 60 days straight:

Chris started his diet on October 1, 2010, and didn’t use any milk, butter or cheese toppings for mashing his potatoes. The only way he had them were fried, boiled, mashed, steamed, chipped or baked. His diet continued for 60 straight days and ended on November 29, 2010.

Also here’s an incredibly corny video if you prefer that format.

Chris wasn’t trying to lose weight. In an interview conducted years later, he said, “I was kind of hoping to be alive at the end of the 60 days… I wasn’t trying to lose weight.” He was 197 pounds at the start of his diet and he describes himself as “six foot one and a half”, so his starting BMI was about 26, just slightly overweight. He seems to have been eating a pretty healthy diet beforehand and he wasn’t seriously overweight, which is why he didn’t think he would lose weight. In fact, he based his daily potato consumption off of a calculation of how much he would need to eat to maintain his starting weight. In response to an early comment on his blog, he said, “I’m eating 20 potatoes a day because that’s how many I’ll have to eat to maintain my current weight.”

But despite his best efforts, by the end of the 60 days, he weighed 176 lbs, a loss of 21 lbs to a BMI of 23.2. His cholesterol also went from 214 to 147, and his glucose went from 104 to 94. In fact, seems like almost everything that could be measured improved: “My cholesterol went down 67 points, my blood sugar came down and all the other blood chemistry — the iron, the calcium, the protein — all of those either stayed the same or got better.” (Here’s a page where someone has compiled a bunch of these numbers.)

Chris did all this in consultation with his doctor, and he does suggest that you have to have a baseline level of health for this to be safe: 

Chris Voigt didn’t go on 20 potatoes and a diet blindly. He first carried out thorough consultations with his dietician and doctor to be sure that he could actually live on potatoes for 60 days straight. After all, you need hale and hearty kidneys for processing the excessive potassium provided by 20 potatoes every day. In addition, you should have also stored ample amounts of necessary nutrients that are lacking in potatoes, for instance vitamin A, for avoiding any harmful side effects.

Those were his results. What was the diet like? 

In the abstract, Chris describes his diet like this

Literally, I just ate potatoes and nothing else. There were a few seasonings, but no gravy, no butter, no sour cream, and just a little bit of oil for cooking. That was it.

That isn’t quite enough detail for our purposes. But older archives of Chris’s site have the blog, which gets a lot more specific. Read it for yourself for the full story, but here are some highlights, focusing on what kinds of potatoes he ate and how he prepared them:

Day 1 – So I had 5 baked red potatoes for breakfast, mashed potatoes with a little garlic seasoning for lunch, and while my family had all the fixing at the steakhouse celebrating my wife’s birthday, I had garlic mashed potatoes and an order of steak fries. The all potato diet wasn’t too bad today, but I did cringe a little when everyone had ice cream for dessert.

Day 2 –  I’m really struggling to eat enough calories. I had two baked potatoes this morning with a couple shots of Tabasco sauce, a serving of mashed potatoes sprinkled with a few BBQ potato chips for a change in texture, and another serving of mashed potatoes and 5 roasted small red potatoes. I didn’t hit the 2200 calories I was hoping for today. I didn’t realize how filling the potatoes would make me feel.

Day 4 – My wife made me 3 pounds of roasted red potatoes that were lightly coated in olive oil with some of her special seasonings. While I made two containers of russet mashed potatoes, one with chives fresh out of our garden and one with a Thai herb/pepper paste I’ve never had before. My wife tells me the paste goes a long way and be careful not to use too much.

Day 6 – I was in potato Nirvana tonight. My wife boiled a bouillon cube with potato starch to make me “psuedo gravy”. It was awesome! She smothered Yukon Gold and Purple potato slices in this gravy and baked it in the oven for an hour. Then cooked homemade yellow and purple chips with artifical sweetner and cinnamon for dessert. It was heaven for a flavor deprived husband. I would marry her all over again because of this!

Day 11 – So one thing people keep asking about is, “What about my weight?” I’ve been hesitant to talk about this because I don’t want people to think of this as a weight loss diet. It is not, and it’s not something I want people to replicate. … So let me step down from my nutrition soap box and talk about weight. I started this diet at 197 pounds. I’m six foot one and a half so according to my BMI, I was a little over weight. I should be in the 175-185 range. Right now, I’m at 189 pounds. Most of that weigh loss happened early, only because I was struggling to eat enough potatoes. I seemed full the whole time so it was hard to keep eating. But now, my weight loss has become more stable.

Day 15 – I feel good. Lot’s of energy, I’m dropping a few pounds which I needed to, and no weird side effects. And mentally, I think I’ve found my groove. Weekdays are pretty easy but weekends are a little tougher, still have desires for other foods but I think those a waning a bit as I get further into this diet.

Day 19 – So my family had potstickers last night while I had roasted red potatoes. For the potstickers, my wife made a dipping sauce that I tried on my red potato wedges. It was pretty good. The sauce was soy sauce, ginger, and some off the shelf dry asian seasoning. It was a nice change of pace. It added a flavor I haven’t had in a long time.

Day 22 – I had about a pound of hash browns this morning for breakfast, two pounds of mashed potatoes with black pepper for lunch, which means I have to eat close to 4 more pounds before bed. I’m leaning towards baked potatoes with balsamic vinegar for dinner but I’m not sure I’m ready for 4 pounds of it.

Day 24 – So here is a new one for you that my wife made up. Fake ice cream made from potatoes. She took 1/2 cup cocoa powder, 1/2 cup artificial sweetner, and a little water to make a chocolate sauce. Then mixed it with about 2 cups of “riced” potatoes and ice. Blended it and put in freezer. It was actually really good, ju…st a strange texture though. I love my wife! What a treat!

Day 26 – I brought my food for the day and stuffed it in the office fridge. Two pounds of purple mashed potatoes topped with garlic salt, 6 smalled baked red potatoes that I’ll probably put balsamic vinegar on, and about 10 oz of gnocchi made with riced potatoes and potato flour, then lightly fried. Can’t boil them because they fall apart since they don’t have the egg in them that you would normally use.

…  I drove to Spokane Sunday night and caught an early flight to Boise the next day. Must remember to prepare better! Nearly starved! I broke into a small emergency stash of instant potatoes I had with me for breakfast, had 3 small bags of …chips and 1 baked potato for lunch, and an order of fries at McD’s for dinner.

Day 28 – So here is what I had yesterday to eat. About 2 pounds of roasted red potatoes lightly seasoned and with a little olive oil, 3 pounds of purple mashed potatoes sprinkled with garlic salt, and about a pound and a half of “riced” potatoes that were fried up lightly. It was kind of like light fluffy hash browns. And a few handfuls of potato chips for a change in texture.

… think about how weird and unusual this diet is. Health professionals actually suggested I include some fries and chips prepared in healthy oils as part of my diet to make me more healthy during this diet. Doesn’t that sound so weird out loud or written in this blog? You have to remember that there is absolutely no fat in a potato, no fat in any of the seasonings or herbs I’m eating. But there are 2 fatty acids that are essential to bodily functions and are needed by your body. The healthy oils from the fries and chips are supplying me those fatty acids. Without them, I would not look or feel very good at the end of these 60 days. The take home message, you need those fatty acids to live but the reality for most people is that we eat too many of them. Live in moderation!

Day 33 – Got out of the house this morning without any seasonings for my spuds. So far, I’ve eaten 6 boiled, yellow flesh, plain potatoes. You know…I really think this is getting easier. I’m not having the intense cravings for other foods that I use to have. Maybe I’ve found my groove.

…  I thought I’d take a moment to answer a couple questions I always get from folks about the diet. One is, “Are you taking any supplements?” No. This diet is about nutrition, there are so many nutrients in potatoes that you could literally live off them for an extended period of time without any major impacts to your health. If I could take supplements, I think you could probably do this diet for a really long time! Also, I get asked about beverages. I drink mostly water, but can have things that don’t add calories or any major nutrients. I do drink some black coffee, plain black tea, or an occasional diet soda.

Day 45 – I just ate about a kilo of purple mashed potatoes for dinner tonight. But I think I added too much garlic salt. Probably shouldn’t do any major kissing tonight. 🙂

Day 50 – Just in case I’m subjected to a lie detector test at some point, I have to come clean on 3 incidents. There were 3 separate times in the previous 50 days where I was making my kids lunch, peanut butter and jelly sandwiches, and without thinking, it was more of a reflex move, I licked clean the peanut or jelly that had gotten on my fingers. Its been bugging me so I needed to share.

Day 60 – So here are most of the stats from my latest medical exam and how it compares to where I was prior to the start of the diet. Weight, started at 197, finished at 176. Cholesterol, started at borderline high of 214, finished at 147. Glucose, started at 104, dropped to 94. So improvements in each of those catagories. I don’t have a hard copy yet, will try to get that tomorrow and will post online. Me Happy!!

Day 61 – (Diet officially over) Its funny because I still have yet to eat something else besides potatoes. I’ve been a little busy this morning so I wasn’t able to pack a lunch or breakfast. But the fridge in our office still had a couple of my potato only dishes. So guess what I had for my first meal at the end of the diet. Potatoes! Hopefully that will change later today. And I bet there will still be potatoes tonight, but with something on them or with them!

… One more thing, a few new folks have joined our little community and have sent me questions about the diet. First, I took no other supplements. It literally was just potatoes, seasonings, and oil for cooking. Now there were a few things we did classify as seasonings since they didn’t really add any significant nutrients, such as Tabasco Sauce which is really just dried peppers and vinegar. Had balsalmic vinegar a few times, and an occasional bouillon cube that was used in mashed potatoes or mixed with potato starch to form something like gravy. THe cubes were 5 calories and really only added sodium to the diet, which we consider a seasoning. 

Day 63 – A big thank you to the Washington Beef, Dairy, and Apple producers. They, along with the Washington Potato Commission, hosted a dinner at the Moses Lake Head Start facility for all the kids and their parents. We did crafts and a short nutrition workshop on the importance of eating healthy, well balanced meals. Not just 20 potatoes a day 🙂 And a big thank you to the staff for all of their work on this and the wonderful Mr. Potato Head they gave me. We had lean beef strips for our tortillas, along with roasted onions, peppers, and potatoes, and apple slices and low fat milk. I sampled everything and wanted to chow down but my doctor has advised me to ease back slowly into other foods. So I’m still eating a lot of potatoes!

On the one hand, Chris took the potato diet very seriously. He really did get almost all his calories from potatoes for about 60 days. He stuck to the plan.

On the other hand, he didn’t take it too seriously. He used cooking oil, spices, and a bunch of different seasonings. He still had coffee, tea, and the “occasional diet soda”. But this didn’t ruin the diet — he still lost weight and gained energy.

The results do seem astounding. More energy, better sleep, lower cholesterol, etc. etc. And how was it subjectively? “I’m really struggling to eat enough calories. … I didn’t realize how filling the potatoes would make me feel. … I feel good.” 

The weight loss results aren’t that extreme, but Chris wasn’t very overweight to begin with. He went from a BMI of 26 to an “ideal” BMI of 23. He didn’t really have many more excess pounds to lose. So let’s take a look at a more extreme example. 

Appendix C: Andrew Taylor

Andrew Taylor is an Australian man who did an all-potato diet for a full year. He started at 334 pounds and he lost 117 pounds over the course of what he called his “Spud Fit Challenge.”

Here’s a video of Andrew before the diet, describing what he is about to attempt. Here’s a video of him 11 months in. And here are some descriptions of how it went

The physical benefits of Taylor’s Spud Fit Challenge remain, he says. “I’ve maintained the weight loss and I’m still free of the daily grind of battling with food addiction. I had a check up a few weeks ago and my doctor was very happy with the state of my health.”

Taylor says that he was clinically depressed and anxious before undertaking his all-potato diet, “which is no longer an issue for me,” he says. “My mental health is much better these days.”

During his challenge, Taylor ate all kinds of potatoes, including sweet potatoes. To add flavor to his meals, he used a sprinkle of dried herbs or fat-free sweet chili or barbecue sauce. If he made mashed potatoes, he only added oil-free soy milk.

He drank mostly water, with the occasional beer thrown in (proof that no man can resist a great brew). Because his diet completely lacked meat, he supplemented with a B12 vitamin.

He also didn’t restrict the amount he consumed. Instead, Taylor ate as many potatoes as he needed to satisfy his hunger. For the first month, he didn’t work out at all and still dropped 22 pounds, but then he added 90 minutes of exercise to his routine every day.

 “I feel amazing and incredible! I’m sleeping better, I no longer have joint pain from old football injuries, I’m full of energy, I have better mental clarity and focus,” he writes on his site.

Like Chris Voigt, Andrew made sure to get regular checkups

Taylor said has had medical supervision, including regular blood tests, throughout the year. His cholesterol has improved and his blood-sugar levels, blood pressure and other health indicators are good, he explained. He feels “totally amazing,” noting he no longer has problems with clinical depression and anxiety, sleeps better, feels more energetic and is physically stronger.

Andrew is now running spudfit.com. For the specifics of Andrew’s diet, the FAQ is pretty detailed: 

A combination of all kinds of potatoes, including sweet potatoes. I used minimal dried and fresh herbs, spices and fat-free sauces (such as sweet chilli, tomato sauce or barbecue sauce) for a bit of flavour. I also use some soy milk (no added oil) when I make mashed potatoes.

I drank only water and the occasional beer. I didn’t drink any tea or coffee but I’ve never liked them anyway. If you want to drink tea or coffee I think that would be fine as long as you use a low fat (no added oil) plant based milk.

For the first month I did no exercise and still lost 10kgs. After that I tried to do around 90 minutes of training every day. I DID NOT exercise for weight loss, I did it because for the first time in years I had excess energy to burn, enjoyed it and it made me feel good. I think that whatever the amount of exercise I did, my body adjusted my hunger levels to make sure I take in enough food. If I didn’t let myself go hungry then I was fine.

Rule 1: Do your own research and make educated decisions – don’t just do things because you saw some weird bloke on the internet doing it! Also get medical supervision to make sure everything is going well for you, especially if you are taking any medications.

Rule 2: Eat a combination of all kinds of potatoes, including sweet potatoes. I have minimal herbs, spices and fat-free sauces for a bit of flavour. I also use some soy (or other plant-based with no added oil) milk when I make mashed potatoes. Also take a B12 supplement if you plan on doing this for longer than a few months. Definitely no oil – of any kind – or anything fatty such as meats, cheeses, eggs or dairy products (even lean or low-fat versions).

Rule 3: DO NOT RESTRICT OR COUNT CALORIES. I eat as much as I like, as often as I like, I do not allow myself to go hungry if I can help it.

I used a non-stick granite pan and fry in water or salt reduced vegetable stock. When I used the oven I just put the potatoes straight on the tray. I also liked to cook potatoes in my pressure cooker and my air fryer.

I felt amazing and incredible and I still do! My sleep improved, joint pain from old football injuries went away, I gained energy and improved mental clarity and focus. Also I lost 52.3 kilograms (117 pounds) over the course of the year. By far the best part is that I no longer suffer with clinical depression and anxiety.

I tried to keep it as simple as possible. I didn’t own an air fryer or a pressure cooker or any other special gadgets. Most of what I ate was either boiled, baked or mashed potatoes. I would make a really big batch of one type and then eat it for a day or two until it was gone and then repeat.

(did you eat the skins?) I did but if you don’t want to that’s ok too.

This is the most surprising thing of all, I can’t explain why but I’m not at all bored of my potato meals.

Over the month of January, following the completion of my Spud Fit Challenge, I lost another 2kg (4lbs). This took my total weight loss to 55kg (121lbs) and meant I weighed the same as I did when I was 15 years old – 96kg (211lbs)! Since then I’ve stopped weighing myself so I can’t be sure of what I actually weigh, my new clothes still all fit though and I still feel good so I guess my weight is around the same (nearly 15 months later at the time of writing this).

This diet looks pretty similar to what Chris did. All potatoes but not wildly strict — he would have seasonings and sauces and even an occasional beer. The big difference is that Andrew studiously avoided added oils, and took a B12 supplement. 

The B12 seems like a good addition to us, especially since Andrew was doing this for a full year, because potatoes contain almost no B12. Hard to say if avoiding oil was important but using oil didn’t keep Chris Voigt from seeing a lot of benefits from potatoes. On the other hand, Andrew didn’t seem to miss it. 

Appendix D: Penn Jillette 

Penn Jillette, of the famous magician duo Penn & Teller, lost over 100 lbs, down from “probably over 340”, on a diet that started with a 2-week period of nothing but potatoes.

You can hear him describe his process in this video, but here are a few choice details: 

I didn’t mind not being energetic and stuff. But I started having blood pressure that was stupid high like, you know, like English voltage, like 220 even on blood pressure medicine.

If you take medical advice from a Las Vegas magician you are an idiot who deserves to die. You have to do this for yourself and with your proper medical professionals.

And one of the really good ways to do that that worked tremendously for me is what’s called the mono diet which is just what you think from the root, eating the exact same thing.

And I could have chosen anything. I could have chosen corn or beans or whatever. Not hot fudge but anything. And I chose potatoes because it’s a funny thing and a funny word.

For two weeks I ate potatoes, complete potatoes – skin and everything and nothing added, nothing subtracted. When I say nothing subtracted I mean no skin taken off but also no water. You can’t cut it up and make it chips in a microwave. Don’t take water out of it. 

Leave the potato completely – so that means baked or boiled and not at any mealtime. You don’t get up in the morning, eat a potato. You don’t eat it at lunch or dinner. Mealtimes are obliterated. When you really need to eat, eat a potato. And over that first two weeks I lost I believe 14 pounds. So already I’m a different person.

Then after that two weeks I went to, you know, bean stew and tomatoes and salads. But still no fruit and no nuts. Certainly no animal products. And I lost an average – these words are careful – an average of 0.9 pounds a day.  So I took off pretty much all the weight in three or four months, in a season, in a winter.

And that was 17 months ago. So I’ve kept the weight off for 17 months. Now two years is magic. Very few people keep it off for two years. I’ve got seven more months to go. I think I have a shot at it.

I feel better. I’m happier. I’m off most of my blood pressure meds. Not all of them, it takes a while for the vascular system to catch up with the weight loss. I have more fun. I believe I’m kinder.

All of that having been said now that I’m at target weight I also – this is important – I also didn’t exercise while I was losing the weight. Exercising is body building. It’s a different thing. Wait until you hit the target weight, then you exercise. Then it’s easy. Then it really does good. But while you’re losing weight make it winter. Sleep a little more. Get sluggish. Let your body just eat the fat that you’ve stored up just the way you should. Hibernate a little bit. Let it eat the fat. Be a little bit like a bear.

Again, a pretty impressive story. And, as of 2019, he seems to be keeping it off.  

Appendix E: Brian & Jessica Krock

Penn’s example inspired a similar attempt from the Krocks, a couple who have jointly lost over 220 lbs starting with two weeks of an all-potato diet

He was 35 when we started this journey and tipped the scales at 514 pounds. My own weight was approaching 300 pounds and my health was starting to suffer. High blood pressure, anxiety and acne were just the start of my issues. 

We picked a start date on the calendar (June 22, 2018 – which also happened to be the 11th anniversary of when we first started dating) and started doing research. The first book I read was Penn Jillette’s Presto!: How I Made Over 100 Pounds Disappear and Other Magical Tales. It was exactly what I needed to get into the right frame of mind for starting this journey. It wasn’t a book from a doctor or a nutritionist or someone telling me why eating the way I did was going to kill me. It was a book from someone who KNEW the real struggle we have dealt with for years. Someone who spend years overweight, LOVED food, and didn’t buy into the whole “eat in moderation” philosophy a lot of our past failed diets relied on.

The first day of potatoes sucked. I seriously contemplated quitting during the FIRST day. After eating my first round of potatoes, I literally walked from our apartment to a grocery store to look at the extra cheesy hot-and-ready pizza I thought I needed. I gazed at the pizza and walked around the store looking for something to eat. Luckily, I was able to keep it together and walk out of the store and back home to my pantry full of potatoes.

I’m not trying to be dramatic, but it was seriously one of the hardest things I’ve done in my life. It took more will power than I thought either of us had.

Even when we started the two weeks of potatoes, we still weren’t sure what the heck we were supposed to do after that. We knew it was vegan. We knew we wouldn’t be able to use added salt, sugar, oil, etc. But that was about it. So we did a lot of research during those two weeks of eating nothing but potatoes. From what I could tell, after the two weeks of potatoes, Penn Jillette followed a whole food, plant-based diet for the most part, so we decided to stick with that.

 We will never go back to eating the way we used to eat. As hokey as it might sound: This is not a diet – it is a lifestyle. We know if we go back to our old ways, we’ll gain the weight back again. The best part is… we don’t want to go back to how we ate before! We actually enjoy food more now than we did before. We have a better relationship with food. We feel like we eat MORE variety now. Eating a whole food, plant-based diet has opened our minds and palates to a new world of food that we would not have given a second thought to before.

They seem to have had a harder time than the other examples we looked at. But we also notice they are the heaviest people we’ve looked at so far, so it’s not hard to imagine that it might have been roughest for them. But even so, it seems to have worked. 

As far as we can tell, they are following Penn’s approach over what Chris and Andrew did — no oil or nothin’, just potatoes. Our sense is that this is probably more hardcore than what is necessary but like, more power to them. On the other hand, this may be part of what made it so difficult. Even Andrew used seasonings! Detailed instructions for how they prepare Taters appear in their videos.

The Krocks are still making videos, and if you look at their channel, they seem to have kept a lot of weight off.

Appendix F: Potato Hack

We are also going to talk about potato hack. This is not a case study per se but it is another all-potato approach, and one that has lots of very positive reviews on Amazon, for whatever that’s worth.

Per the website, “The Potato Hack (aka The Potato Diet) is an extremely effective method for losing weight without experiencing hunger.”

The Potato Hack Overview has this to say about the details: 

Red and yellow potatoes work the best, because after they are boiled they keep longer than Russet potatoes, which tend to get mushy quicker. However, Russet potatoes do work. Try all potato types.

Sweet potatoes are not potatoes. They can work for some people, but not nearly as well. If you can not handle nightshades, purple yams with white flesh can be a substitute. Weight loss is likely to be slower when you don’t use regular potatoes.

The only way to make the potato fattening is to process it and cook it in oil. So avoid fries and chips. For the potato hack to work the potatoes need to be cooked only in water. Boil, steam, or pressure cook.

When cooked potatoes are cooled overnight in the refrigerator they develop something called resistant starch. Resistant starch is beneficial to our gut flora, balances blood sugar, and other additional health benefits. These resistant starches are not digested in the same manner as regular calories, so they have the effect of reducing the calories of potatoes.

Refrigerating cooked potatoes overnight will reduce the calories by about 17%. The potatoes can be reheated before eating without losing any of the resistant starch.

The potato hack will still work if you don’t refrigerate the potatoes, so although this step is encouraged, it is optional.

Eat the potatoes plain. Salt if you must. You can add a splash of malt or red wine vinegar if a blood sugar spike is a concern, although cooling the potatoes will reduce the glycemic response.

To get the full benefit of the potato hack, it is strongly advised to eat the potatoes plain. You are teaching your brain how to get full without flavor. This is the opposite approach taken in dieting where one continues to get flavorful food but in a restrictive manner.

With the potato diet, do not walk away from the table hungry. Eat until full.

This is a little more finicky (what potatoes to use, how to store them, etc.) but overall looks a lot like the other examples we’ve considered. 

The hack also links to some testimonies, including this one guy’s particular approach. We’ll include it here because it gives an unusual amount of detail about purchasing and preparation:  

If your time is valuable to purchase organic, because you will not need to peel the potatoes, plus they have more nutrition. If you want to save money, purchase non-organic. I cycle between both options.

The three most common options for potatoes are going to be red, yellow, and russet. 98% of the time I will purchase red or yellow. They hold up much better structurally when you take them in and out of the refrigerator over a day or two.

Russet potatoes get mushy quickly. The only time I get Russet is if I get a really good price and I know I’m doing a strict potato hack, so I’m not using those potatoes two days later.

I’ve boiled so many potatoes in the last two years, my hands have developed muscle memory as if I were driving a manual car. Here is how I’ve optimized my potato preparation.

1. Peel directly into colander if the potatoes are not organic.

2. Place the potato directly into the cleaned and dried storage container.

3. Fill the storage container. When I first started hacking, I would weigh the potatoes. Once I figured out my container could hold 5.5 pounds, then I put my scale away.

4. Remove each potato. If it is small, place it in a stockpot, otherwise chop it into parts. For me, a medium potato is 2 or 3 parts. A large potato will be more. My goal is to have approximately equal size potato parts. I want them to boil at the same rate.

5. Once that is complete, I rinse the potatoes in the stockpot.

6. Refill stockpot with clean water and boil.

7. While the potatoes are boiling, empty peels in a compost bin.

8. Boil until done to your liking. I tend to cook mine a little longer than Tim Steele describes in his book The Potato Hack, but whatever you like is the right answer. Experiment.

9. Drain and let potatoes cool. The reason I want the potatoes to cool is that if I don’t, the steam will collect on the roof of the storage container and drain down onto the potatoes, making them mushy more quickly. If I want the potatoes to cool fast, I will spread them on a cookie sheet and place them outside (provided outside is cooler than inside).

10 Put the cooled potatoes in the storage bin and refrigerate.

That is my optimized path. I’m sure you’ll find your own.

Book Review: A Square Meal – Part II: Politics

The book is still A Square Meal: A Culinary History of the Great Depression, recommended to us by reader Phil Wagner, and Part I of the review is here.

Condescension, Means Testing, and Infinite Busybodies

The other big thing we learned from A Square Meal, besides the fact that food in the 1920s was bonkers, is that the Great Depression brought out the absolute worst in the American political machine: the tendency for condescension to the unfortunate, constant means testing to make sure the needy are really as needy as they say, and infinite busybodies of every stripe.

Some of this was just standard government condescension. In WWI, the United States Food Administration tried to convince Americans that dried peas were a fine substitute for beefcake, and that “Wheatless, Eggless, Butterless, Milkless, Sugarless Cake” was a food substance at all. Sure.

When the Great Depression hit, things got steadily worse. Homemakers were encouraged to turn anything and everything into casseroles, which had the benefit of making their contents indistinguishable under a layer of white sauce and bread crumbs. The housewife could serve unappetizing food or leftovers over and over again without her family catching on, or at least that was the idea. Among other things this gives us this unusual early example of the overuse of the term “epic”:

Whatever the answer, [the casserole] is bound to be an epic if mother is up to the minute on the art of turning homely foods into culinary triumphs

Some people in government seemed to be confused — they seemed to think that the food issues facing the nation were a matter of presentation, that food just didn’t look appetizing enough. It’s hard to interpret some of these suggestions in any other light, like the idea that good advice for Americans in the Depression could be, “to impart a touch of elegance to a bowl of split pea soup, why not float a thin slice of lemon on top and sprinkle it with some bright red paprika and finely chopped parsley.” Or the suggestion that beans could be fried in croquettes to make them more appealing. Authorities trotted out “reassuring” announcements like: 

The fact that a really good cook can serve better meals on a small budget than a poor cook can serve on the fat of the land suggests that the fault may be not in the food material itself but in the manner in which the food is prepared and served, and therein lays a tale!

But what really grinds our gears isn’t the condescension, it’s the means testing. The second half of the book is mostly depressing stories about the government refusing to provide basic aid to starving families, or screwing up one relief program after another with means testing, or other things along these lines.

American society at the time was firmly anti-charity. People thought that everyone on the breadline could be divided into the “deserving poor” and the “undeserving poor”, and it was their job to search out which was which. They seemed to believe that even one whiff of assistance would immediately turn any hardworking, self-respecting American into a total layabout. 

People in the 1930s are always saying things like, “if a man keeps beating a path to the welfare office to get a grocery order he will gradually learn the way and it will be pretty hard to get him off that path.” They really seemed to believe in the corrupting power of government support, to the point where they were often afraid to even use the word “charity”.

Before the Great Depression, there was very little history of big-picture welfare. The support that society did provide was administered locally, and not very well administered at all:

The poor laws combined guarded concern for needy Americans with suspicions that they were complicit in their own misfortune. Under the poor laws, the chronically jobless were removed from society and dispatched to county poorhouses, catchall institutions that were also home to the old, infirm, and mentally ill. Those who could ordinarily shift for themselves but were temporarily jobless applied to public officials, men with no special welfare training, for what was known as outdoor or home relief, assistance generally given in the form of food and coal. To discourage idlers, the welfare experience was made as unpleasant as possible. Before applying for help, the poor were made to wait until utterly penniless, and then declare it publicly. When granting relief, officers followed the old rule of thumb that families living “on the town” must never reach the comfort level of the poorest independent family. The weekly food allowance was a meager four dollars a week—and less in some areas—regardless of how many people it was supposed to feed. Finally, it was customary to give food and coal on alternate weeks, providing minimal nourishment and warmth, but never both at the same time.

Journalists called people who received government assistance “tax eaters”. When support from the town was forthcoming, it looked like this: 

…the board made all relief applicants fill out a detailed form with questions like: Do you own a radio? Do you own a car? Do you spend any money for movies and entertainment? Did you plant a garden? How many bushels of potatoes do you have? The board gave aid in the form of scrip, which now could only be used to purchase the “necessities of life” at local stores: “flour, potatoes, navy beans, corn meal, oatmeal, coffee, tea, sugar, rice, yeast cakes, baking soda, pepper, matches, butter, lard, canned milk, laundry soap, prunes, syrup, tomatoes, canned peas, salmon, salt, vinegar, eggs, kerosene.”

The Manhattan breadline is emblematic of the Great Depression, so we were sort of surprised at just how much people at the time hated them, even very mainstream sources. You’d think that giving out bread to the starving would be one of the more defensible forms of charity, but people loathed it. And none more than the city’s social workers, described as the breadlines’ “harshest critics”:

Welfare professionals with a long-standing aversion to food charity, social workers condemned the breadlines as relief of the most haphazard and temporary variety, not much different from standing on a street corner and handing out nickels. The people who ran the breadlines, moreover, made no attempt to learn the first thing about the men they were trying to help, or to offer any form of “service” or counseling. The cause of more harm than good, the breadlines were humiliating and demoralizing and encouraged dependence, depriving able-bodied men of the impulse to fend for themselves. Social workers were adamant. Breadlines were the work of fumbling amateurs and “should be abolished entirely; if necessary by legal enactment.”

As the Depression dragged on and things became worse, more relief did come. But when it came, the relief was invasive. Housewives were told not only what to cook, but where to shop. Some women had to venture far outside their own neighborhoods to use food tickets. Social workers dropped in on schools to criticize the work of teachers, in particular the tendency of teachers to be overly “sentimental” or “solicitous”. They feared that schoolteachers lacked the “well-honed detective skills” required to distinguish between whining and genuine tales of woe. 

To ascertain that applicants were truly destitute, officials subjected them to a round of interviews. Candor was not assumed. Rather, all claims were verified through interviews with relatives and former employers, which was not only embarrassing but could hurt a man’s chances for employment in the future. More demeaning, however, were the home visits by TERA investigators to make sure the family’s situation was sufficiently desperate. Investigators came once a month, unannounced, anxious to catch welfare abusers. Any sign that the family’s finances had improved—a suspiciously new-looking dress or fresh set of window curtains—was grounds for cross-examination. If the man of the house was not at home—a suggestion that he might be out earning money—investigators asked for his whereabouts, collecting names and addresses for later verification. Finally, though instructed otherwise, investigators were known to reprimand women for becoming pregnant while on relief, the ultimate intrusion.

Families lived in dread of these monthly visits, terrified they would be cut off if it was discovered that one of the kids had a paper route or some similar infraction.

In some areas, including New York City, “pantry snoopers” accompanied women to the market to confirm that all parties (both shopper and shopkeeper) were complying with TERA’s marketing guidelines. More prying took place in the kitchen itself, where investigators lifted pot covers and peered into iceboxes on the lookout for dietary violations.

Relief was often inadequate. Public officials were sometimes able to set relief levels at whatever amount they saw fit, regardless of state or federal guidance. Some of them assumed that poor families would be able to provide their own farm goods, but often this was not the case. In some places officials reasoned that poor workers would be easier to push around, and kept food allowances low to keep them in line. There was also just straight-up racism: 

Six Eyetalians will live like kings for two weeks if you send in twenty pounds of spaghetti, six cans of tomato paste and a dozen loaves of three-foot-long bread. But give them a food order like this [$13.50, state minimum for six persons for half a month], and they will still live like kings and put five bucks in the bank. Now you ought to give a colored boy more. He likes his pork chops and half a fried chicken. Needs them, too, to keep up his strength. Let him have a chicken now and then and maybe he’ll go out and find himself a job. But a good meal of meat would kill an Eyetalian on account of he ain’t used to it.

Families on relief who asked for seasonings on their food, like vinegar or mustard, were refused on the grounds that they might “begin to feel too much like other families”. Officials who were afraid that cash handouts to the poor might encourage dependence instead used that money to hire a resident home economist to help the poor make better use of what little they had.

As with modern means testing, this seems heart-breakingly callous. All these “supervisory” jobs intended to keep poor people from getting too much relief look suspiciously like a method for taking money that’s meant to help starving families and using it to pay the middle class to snoop on their less fortunate neighbors. Everyone loves giving middle-class busybodies jobs in “charity” work, no one seems to worry all that much about getting food to malnourished children. 

To be fair, no one expected that the relief would have to go on for years. Everyone thought that the panic was temporary, that it would all be over in a couple of months. This doesn’t make it much better, but it does explain some of the reluctance.

Another surprising villain in all this is, of all things, the American Red Cross. Over and over again, the Red Cross either refused to provide aid or gave only the smallest amounts, even when people were literally starving to death. They sent officials to areas stricken by drought and flood, who reported back that there was not “evidence of malnutrition more than exists in normal times” or brought back stories about an old man complaining that the Red Cross was feeding him too well. Meanwhile, actual Red Cross workers were reporting circumstances like this, from Kentucky: 

We have filled up the poor farm. We have carted our children to orphanages for the sake of feeding them. There is no more room. Our people in the country are starving and freezing.

The Red Cross’s reasoning was the same as everyone else in government: “If people get it into their heads that when they have made a little cotton crop and tried to make a corn crop and failed and then expected charity to feed them for five months, then the Red Cross had defeated the very thing that it should have promoted, self-reliance and initiative.” Actually this statement is on the friendlier side of things; another Red Cross official, after touring Kentucky, wrote: “There is a feeling among the better farmers in Boyd County that the drought is providential; that God intended the dumb ones should be wiped out; and that it is a mistake to feed them.”

Was Hoover the Villain? 

This brings us to a major question — namely, was Herbert Hoover the real villain of the Great Depression? 

At first glance it certainly looks that way. Hoover consistently blocked relief bills in Congress. He had a clear no-relief policy, and he stuck to it throughout his time as president. And he did send the US Army to drive a bunch of poor veterans out of DC

(He also lived in incredible opulence during his time in the White House. Always black tie dinners, always a table awash in gold, always fancy gourmet foreign food, always a row of butlers all exactly the same height. As they say, “not a good look”.)

But when you start looking at things in more detail, it becomes more complicated. It may seem naïve, but Hoover really thought that Americans would come together and take care of each other without the need for government assistance. He seemed to oppose relief because he thought that the federal government stepping in would make things worse. In one speech, he promised that “no man, woman or child shall go hungry or unsheltered through the coming winter” and emphasized that voluntary relief organizations would make sure that everyone was taken care of. He might have been wrong, but this doesn’t look villainous. (He also said, “This is, I trust, the last winter of this great calamity.” It was 1932.)

In a pretty bizarre state of affairs, he also seems to have been thwarted by the Red Cross at every turn, especially its chairman John Barton Payne. It makes sense that Hoover approved of the Red Cross, since it was one of the voluntary generous organizations he liked so much. What’s strange is how frequently the Red Cross just didn’t do jack, even when asked.

For example: In 1930, Hoover pressured the Red Cross to help out with drought relief in the Mississippi delta. The Red Cross agreed to give out $5 million in aid, but by the end of the year they had spent less than $500,000, mostly on handing out seed to farmers. 

Another time, Hoover went to the Red Cross to help provide relief to striking miners. This time the Red Cross refused, though again they offered seed to the miners (it’s unclear if there was even arable land near the mine). So Hoover went to a Quaker relief organization instead, and the Quakers agreed to help feed hungry children in the mining areas. Hoover struck a deal where the Red Cross would provide $200,000 to help the Quakers out. The Quakers waited two months before the Red Cross refused again. So the Quakers went ahead without them.

Somehow Hoover never turned his back on the Red Cross. Maybe he just liked the idea of aid organizations too much to realize that this one kept undermining him in times of crisis. 

But the other thing to understand about Hoover is that, despite his gruff no-handouts exterior, inside he was a bit of a softie. He stuck to his guns on the subject of cash relief, but he usually found a way to help without breaking his own rules. When the Red Cross refused to help the Quakers, Hoover rooted around and found $225,000 in an idle account belonging to a World War I relief organization, and sent that instead. In the flood of 1927 (when he was secretary of commerce), he refused to allocate federal funds directly, but he did have the U.S. Army distribute rations, tents, and blankets, organized local governments to rebuild roads and bridges, and got the Red Cross to distribute seeds and farm implements (the only thing they seem comfortable with). This was a huge success, and a big part of what won him the 1928 presidential election!  

The reason Hoover believed in the no-relief approach was simple — he had used it many times before, and it had always worked. He had a long track record of dealing with this kind of crisis. Before he was president, his nickname was “The Great Humanitarian” for the relief work he had done in Europe during World War I. People saw him as an omnicompetent engineering genius, and the reputation is at least partially deserved. It’s hard to overstate just how popular he was before the Depression: He won the election of 1928 with 444 electoral votes to 87, a total landslide.

Hoover thinks that attitude is the key to fighting financial panics, because this is exactly what he saw in 1921. There was a big stock market panic, which Hoover recognized was at least partially psychological. So he put out a bunch of reassuring press releases, told everyone that the panic was over, and sure enough, the market recovered.

So when the same thing happens in 1929, he figures the same approach will work. He does everything he can to project confidence and a sense of business as usual, and tries not to do anything that will start a bigger panic. This includes no federal relief — because if the federal government starts handing out money, that must mean things are REALLY bad. It makes a certain amount of sense, it did work for him in the past, but for some reason, it doesn’t work this time around. Maybe blame the Red Cross. 

FDR definitely jumped in to take advantage of the confusion. As then-governor of New York, he started implementing the kind of relief plans that Hoover refused to consider. He gave direct food relief. He used the word “charity”. And when he ran for president, he made it very clear that he thought the federal government should cover what the states could not, and make sure that no one would starve.

This did win him the election. But afterwards, he started looking a lot more like Hoover and some of his cronies. In his 1935 state of the union address, he said, “continued dependence upon relief induces a spiritual and moral disintegration fundamentally destructive to the national fiber. To dole out relief in this way is to administer a narcotic, a subtle destroyer of the human spirit. It is inimical to the dictates of sound policy. It is in violation of the traditions of America.” We’re right back to where we started. 

FDR rolls out the Works Progress Administration, another program that ties relief to a person’s work. But this isn’t administered much better than the Red Cross. Many workers couldn’t live on the low wages they offered. Even when they could, the jobs lasted only as long as the projects did, so workers often went months without jobs between different programs. 

The Civilian Conservation Corps was for a long time the most popular of these programs, but in 1936, Roosevelt decided to focus on balancing the budget instead. He slashed the program from 300,000 people to about 1,400. Over time, most of the relief burden fell back on state and city governments, many of which descended back into cronyism.

Some of the programs, for migrants and “transients”, were worse, nearly Orwellian:

Before the New Deal, transients were the last group to receive relief under the old poor laws. Now the FTP funded a separate system of transient centers guided by federal regulations meant to guard against local governments’ ingrained cultural biases against drifters and migrant job seekers. In rural areas, transients would be gathered into federal “concentration camps” (a term that had not yet gained its ominous connotations) designed for long-term stays.

As waves of agricultural migrants spread across the United States, by 1940 the FSA had opened 56 camps around the country, 18 of them in California, each accommodating up to 350 families. Administrators nevertheless continued to keep costs as low as possible, following the “rehabilitation rather than relief” rule handed down by President Roosevelt. Rather than give migrants food, the camps taught home economics–style classes on nutrition and food budgeting.

By 1937 everything seems to have fallen apart again, and the authors suggest that the second half of the 1930s was as bad or worse than the first half. In 1938, Roosevelt refused to give any further direct food relief from the WPA coffers. The stories from 1939 are kind of harrowing. 

By 1939, the problems of unemployment and what to do with millions of jobless Americans seemed intractable. The economy continued to sputter along; real prosperity remained an elusive goal; and Americans were losing compassion for the destitute and hungry.  

A Houston, Texas, reporter lived for a week on the city’s $1.20 weekly food handout, eating mostly oatmeal, potatoes, stewed tomatoes, and cabbage, and lost nearly ten pounds. In Chicago, a family of four received $36.50 a month, meant to cover food, clothing, fuel, rent, and everything else. But fuel in the cold Chicago winters was expensive; families had no choice but to cut back on food. In Ohio, the governor again refused to give aid to Cleveland, which ran out of money for nearly a month—called the “Hunger Weeks”—at the end of 1939. The city was reduced to feeding its poor with flour and apples as desperate families combed garbage bins for anything edible. Adults lost as much as fifteen pounds, while children had to stay home, too weak from hunger to attend school. Doctors saw a jump in cases of pneumonia, influenza, pleurisy, tuberculosis, heart disease, suicide attempts, and mental breakdowns.

So whatever Hoover did wrong, he doesn’t deserve all the blame, and the WPA certainly did not end the Great Depression.

Book Review: A Square Meal – Part I: Foods of the ‘20s and ‘30s

[Content warning: Food, culture shock, milk]

They say that the past is a foreign country, and nowhere is this more true than with food. 

The book is A Square Meal: A Culinary History of the Great Depression by Jane Ziegelman and Andrew Coe, recommended to us by reader Phil Wagner. This book is, no pun intended, just what it says on the tin, a history of food during the 1920s and 1930s. Both decades are covered because you need to understand what food was like in the 1920s to understand what changed when the Great Depression battered the world in the ‘30s. 

Home is where the lard-based diet is

We read this book and were like, “what are you eating? I would never eat this.” 

The book picks up at end of World War I, and the weird food anecdotes begin immediately:  

Their greeting back in American waters—even before they landed—was rapturous. Local governments, newspapers, and anybody else who could chartered boats to race out to meet the arriving ships. When the Mauretania, carrying 3,999 troops, steamed into New York Harbor late in 1918, a police boat carrying the mayor’s welcoming committee pulled alongside. After city dignitaries shouted greetings to them through megaphones, the troops who crowded the deck and hung from every porthole bellowed en masse: “When do we eat?!” It became a custom for greeting parties to hire professional baseball pitchers to hurl California oranges at the troops—some soldiers sustained concussions from the barrage—to give them their first taste of fresh American produce in more than a year.

Not that the soldiers weren’t also well-fed at the front lines: 

Despite the privations they had undergone, the Americans held one great advantage over both the German enemy and the soldiers of their French and British allies. They were by far the best-fed troops of World War I.

The U.S. Army field ration in France varied according to circumstances, but the core of the soldiers’ daily diet was twenty ounces of fresh beef (or sixteen ounces of canned meat or twelve ounces of bacon), twenty ounces of potatoes, and eighteen ounces of bread, hard or soft. American troops were always proud that they enjoyed white bread, while all the other armies had to subsist on dark breads of various sorts. This ration was supplemented with coffee, sugar, salt, pepper, dried fruit, and jam. If supply lines were running, a soldier could eat almost four pounds of food, or 5,000 calories, a day. American generals believed that this was the best diet for building bone, muscle, tissue, and endurance. British and French troops consumed closer to 4,000 calories, while in the last months of the war the Germans were barely receiving enough rations to sustain themselves.

The overall food landscape of the 1920s is almost unrecognizable. The term “salad” at the time referred to “assemblages made from canned fruit, cream cheese, gelatin, and mayonnaise,” which the authors note FDR especially hated [1]. Any dish that contained tomatoes was called “Spanish” (a tradition that today survives only in the dish Spanish rice). And whatever the circumstances, there was ALWAYS dessert — even in the quasi-military CCC camps, even in the government-issued guides to balanced meals, even in school lunch programs that were barely scraping by. 

This book also has some interesting reminders that constipation used to be the disease of civilization. In fact, they mention constipation being called “civilization’s curse”. This is why we have the stereotype of old people being obsessed with fiber and regularity, even though that stereotype is about a generation old now, and refers to a generation that has largely passed.

In the countryside, farm diets were enormous and overwhelmingly delicious: 

In midwestern kitchens, the lard-based diet achieved its apotheosis in a dish called salt pork with milk gravy, here served with a typical side of boiled potatoes:

On a great platter lay two dozen or more pieces of fried salt pork, crisp in their shells of browned flour, and fit for a king. On one side of the platter was a heaping dish of steaming potatoes. A knife had been drawn once around each, just to give it a chance to expand and show mealy white between the gaping circles that covered its bulk. At the other side was a boat of milk gravy, which had followed the pork into the frying-pan and had come forth fit company for the boiled potatoes.

The first volume of their oral history, Feeding Our Families, describes the Indiana farmhouse diet from season to season and meal to meal. In the early decades of the century, the Hoosier breakfast was a proper sit-down feast featuring fried eggs and fried “meat,” which throughout much of rural American meant bacon, ham, or some other form of pork. In the nineteenth century, large tracts of Indiana had been settled by Germans, who left their mark on the local food culture. A common breakfast item among their descendants was pon haus, a relative of scrapple, made from pork scraps and cornmeal cooked into mush, molded into loaf pans and left to solidify. For breakfast, it was cut and fried. Toward fall, as the pork barrel emptied, the women replaced meat with slices of fried apples or potatoes. The required accompaniment was biscuits dressed with butter, jam, jelly, sorghum syrup, or fruit butter made from apples, peaches, or plums. A final possibility—country biscuits were never served naked—was milk gravy thickened with a flour roux.

Where farmhouse breakfasts were ample, lunch was more so, especially in summer when workdays were long and appetites pushed to their highest register. With the kitchen garden at full production, the midday meal often included stewed beets, stewed tomatoes, long-simmered green beans, boiled corn, and potatoes fried in salt pork, all cooked to maximum tenderness. At the center of the table often stood a pot of chicken and dumplings, with cushiony slices of white bread to sop up the cooking broth. The gaps between the plates were filled with jars of chow-chow; onion relish; and pickled peaches, cauliflower, and watermelon rinds. The midday meal concluded with a solid wedge of pie. Like bread, pies were baked in bulk, up to a dozen at a time, and could be consumed at breakfast, lunch, and dinner.

Ingredients were prepared in ways that sound pretty strange to a modern ear. Whole onions were baked in tomato sauce and then eaten for lunch. Whole tomatoes were scalloped on their own. 

Organ meats were considered perfectly normal, if somewhat tricky to cook. The book mentions how food columnists had to teach urban housewives about how to remove the “transparent casing” that brains naturally come in, the membrane from kidneys, and the arteries and veins from hearts — not the sort of thing you would expect from a modern food columnist. On hog-killing day, an annual event all over the rural United States: 

The most perishable parts of the animal were consumed by the assembled crowd, the brains scrambled with eggs, the heart and liver fried up and eaten with biscuits and gravy. Even bladders were put to good use—though it wasn’t culinary. Rather, they were given to the children, who inflated them, filled them with beans, and used them as rattles.

There are a lot of fascinating recipes in this book, but perhaps our favorite is this recipe that appears in a section on the many uses of pork lard: 

Appalachian farm women prepared a springtime specialty called “killed lettuce,” made from pokeweed, dandelion, and other wild greens drizzled with hot bacon grease that “killed,” or wilted, the tender, new leaves. The final touch to this fat-slicked salad was a welcome dose of vinegar.

You might expect the urban food situation to be more modern, seeing as it involves less hog-killing. But if anything, it’s stranger. 

To start with, ice cream delicacies were considered normal lunch fare: 

The most typical soda fountain concoction was the ice cream soda, which was defined as “a measured quantity of ice cream added to the mixture of syrup and carbonated water. From there, the imaginations of soda jerks were given free range. Trade manuals such as The Dispenser’s Formulary or Soda Water Guide contained more than three thousand soda fountain recipes for concoctions like the Garden Sass Sundae (made with rhubarb) and the Cherry Suey (topped with chopped fruit, nuts, and cherry syrup). … From relatively austere malted milks to the most elaborate sundaes, all of these sweet confections were considered perfectly acceptable as a main course for lunch, particularly by women. In fact, American sugar consumption spiked during the 1920s. This was in part thanks to Prohibition—deprived of alcohol, Americans turned to anything sweet for a quick, satisfying rush.

Delicatessens and cafeterias, which we take for granted today, were strange new forms of dining. The reaction to these new eateries can only be described as apocalyptic. Delicatessens were described as “emblems of a declining civilization, the source of all our ills, the promoter of equal suffrage, the permitter of business and professional women, the destroyer of the home.” The world of the 1920s demanded an entirely new vocabulary for many new social ills springing up — “cafeteria brides” and “delicatessen husbands” facing down the possibility of that new phenomenon, the “delicatessen divorce.” The fear was that your flapper wife, unable to make a meal in her tiny city kitchenette, or out all day with a self-supporting career, would feed you food that she got from the delicatessen, instead of a home-cooked and hearty meal. 

In all of these cases, the idea was that new ways of eating would destroy the kitchen-centric American way of life — which, to be fair, it did. Calling a deli “the destroyer of the home” seems comical to us, but they were concerned that these new conveniences would destroy the social structures that they knew and loved, and they were right. We think our way of life is an improvement, of course, but you can hardly fault the accuracy of their forecasting.

Really, people found these new eateries equal parts wonderful and terrifying — like any major change, they had their songs of praise as well as their fiery condemnations (hot take: delicatessens were the TikTok of the 1920s). For a stirring example from the praise section, take a look at this lyrical excerpt from the June 18, 1922 edition of the New York Tribune:

Spices of the Orient render delectable the fruits of the Occident. Peach perches on peach and pineapple, slice on slice, within graceful glass jars. Candies are there and exhibits of the manifold things that can be pickled in one way or another. Chickens, hams and sausages are ready to slice, having already been taken through the preliminaries on the range. There are cheeses, fearful and wonderful, and all the pretty bottles are seen, as enticing looking as ever, although they are but the fraction of their former selves [i.e., under Prohibition].”

CHEESES FEARFUL AND WONDERFUL

Sandwiches were not only strange and new, but practically futuristic. “Before the 1920s, sandwiches were largely confined to picnics and free lunches in saloons,” they tell us, “and, with their crusts cut off, delicate accompaniments to afternoon tea.” The writer George Jean Nathan claimed that before the 1920s, there existed only eight basic sandwich types: Swiss cheese, ham, sardine, liverwurst, egg, corned beef, roast beef, and tongue (yes). But by 1926, he “claimed that he had counted 946 different sandwich varieties stuffed with fillings such as watermelon and pimento, peanut butter, fried oyster, Bermuda onion and parsley, fruit salad, aspic of foie gras, spaghetti, red snapper roe, salmi of duck, bacon and fried egg, lettuce and tomato, spiced beef, chow-chow, pickled herring, asparagus tips, deep sea scallops, and so on ad infinitum.”

Like the delicatessen, Americans were not going to take this sandwich thing lying down. Nor would they take it at all calmly! Boston writer Joseph Dinneen described sandwiches as “a natural by-product of modern machine civilization.”

Make your own “biggest thing since sliced bread” joke here, but actually this sandwich craze led directly to first the invention of special sandwich-shaped loaves with flattened tops, and then to sliced bread, which hit the market in 1928.

Frozen foods had also just been invented (frozen foods are soggy and tasteless unless you freeze them really fast; Clarence Birdseye figured out how to do quick freezing by seeing fish freeze solid during an ice fishing trip in Labrador) and were considered a novelty. Yet somehow the brand name Jell-O dates all the way back to 1897.

Many new foods didn’t fit squarely within existing categories. This is sort of like how squid ice cream seems normal in Japan. We have rules about what you can put in an ice cream — mint ice cream makes sense, but onion ice cream is right out — but the Japanese don’t care what we think the ice cream rules are. In the 1920s and 1930s many foods were unfamiliar or actually brand new, so no one had any expectations of what to do with them. For example, the banana, which you know as a fruit, was new enough to Americans that they were still figuring out how the thing should be served

Does seem guaranteed to start conversation! 

We’re sure bananas would be fine served as a vegetable, or with bacon, but this is certainly not the role we would assign to them today.

When the Depression hit, grapefruit somehow found its way into food relief boxes in huge quantities; “so much grapefruit that people didn’t know what to do with it.” Soon the newspapers were coming up with imaginative serving suggestions, like in this piece from the Atlanta Constitution:

It may open the meal, served as a fruit cocktail, in halves with a spoonful of mint jelly in the center or sprinkled with a snow of powdered sugar. It bobs up in a fruit cup, or in a delicious ice. It may be served broiled with meat, appear in a fruit salad or in a grapefruit soufflé pie. Broiled grapefruit slices, seasoned with chili sauce, make an unusual and delightful accompaniment for broiled fish, baked fish or chops.

Some of these sound pretty good; but still, unusual.

Vitamins

The other really strange and exciting thing about this period is that they had just discovered vitamins.

As we’ve covered previously, this was not as easy as you might think. It’s simple to think in terms of vitamins when you’re raised with the idea, but it took literally centuries for people to come up with the concept of a disease of deficiency, even with the totally obvious problem of scurvy staring everyone right in the face. 

Scurvy isn’t just a problem for polar explorers and sailors in the Royal Navy. Farm families living through the winter on preserved foods from their cellar tended to develop “spring fever” just before the frost broke, which the authors of this book think was probably scurvy. Farmwives treated it with “blood tonics” like sassafras tea or sulfured molasses, or the first-sprouted dandelions and onions of spring.

But just around the turn of the century, and with the help of cosmic accidents involving guinea pigs, people finally started to get this vitamin thing right. So the 1920s and 30s paint an interesting picture of what cutting-edge nutrition research looks like when it’s so new that it’s still totally bumbling and incompetent. 

In 1894, Wilbur Olin Atwater established America’s first dietary standards. Unfortunately, Atwater’s recommendations didn’t make much sense. For example, in this system men with more strenuous jobs were assigned more food than men with less strenuous jobs — a carpenter would get more calories than a clerk. This makes some sense, but Atwater then used each man’s food levels to calculate the amount of food required for his wife and kids. The children of men with desk jobs sometimes got half as much food as the children of manual laborers! The idea of treating each member of the family as their own person, nutritionally speaking, was radical in the early 1900s, but the observation that some children were “kept alive in a state of semi-starvation” had begun to attract attention.

People knew they could do better, so following Atwater’s death in 1907, the next generation got to work on coming up with a better system. Atwater had assumed that basically all fats were the same, as were all carbohydrates, all protein, etc. But Dr. Elmer V. McCollum, “a Kansas farm boy turned biochemist”, was on the case investigating fats. 

We really want to emphasize that they had no system at this point, no idea what they were doing. Medical science was young, and nutritional science was barely a decade old. Back then they were still just making things up. These days “guinea pig” and “lab rat” are clichés, but these clichés hadn’t been invented back in 1907. Just like how Holst and Frolich seem to have picked guinea pigs more or less at random to study scurvy, and how ​Karl Koller’s lab used big frogs to test new anesthetics, McCollum was one of the first researchers to use rats as test subjects.

Anyways, McCollum tried feeding his rats different kinds of fats to see if, as Atwater claimed, all fats had the same nutritional value. He found that rats that ate lots of butterfat “grew strong and reproduced, while those that ate the olive oil did not”. He teamed up with a volunteer, Marguerite Davis, and they discovered a factor that was needed for growth and present not only in milk, but eggs, organ meat, and alfalfa leaves. This factor was later renamed vitamin A (as the first to be discovered), and the age of the vitamins had begun. Soon McCollum and Davis were on the trail of a second vitamin, which they naturally called vitamin B.

The public went absolutely bananas for vitamins. It’s not clear if this was a totally natural public reaction, or if it was in response to fears drummed up by… home economists. Yes, home economics, the most lackluster class of all of middle school, represents that last lingering influence of what was once a terrible force in American politics: 

More than anything else, women were afraid of the “hidden hunger” caused by undetectable vitamin deficiencies that could well be injuring their children. … Home economists leveraged those fears. To ensure compliance, bureau food guides came with stark admonitions, warning mothers that poor nutrition in childhood could handicap a person for life. Women were left with the impression that one false move on their part meant their children would grow up with night blindness and bowed knees.

Whatever the cause, vitamins took America by storm. Any food found to be high in one vitamin or another quickly turned that finding to advertising purposes. Quaker oats, found to be high in vitamin B, advertised to kids with a campaign that “teamed up with Little Orphan Annie and her new pal, a soldier named Captain Sparks, who could perform his daring rescues because he had eaten his vitamins.” For adults, they implied that vitamin B would help make you vigorous in bed: 

…a snappy new advertising campaign: “I eat Quaker Oats for that wonderful extra energy ‘spark-plug.’ Jim thinks I have ‘Oomph!’ but I know it’s just that I have plenty of vitality and the kind of disposition a man likes to live with.” What she did with her extra “oomph” was unspecified, but the graphic showed a young couple nose to nose, smiling into each other’s eyes.

Vitamins continued to have this weird grip over the imagination for a long time. As late as the 1940s, American food experts worried that the Nazis had developed some kind of super-nutritional supplement, a “magical Buck Rogers pill,” to keep their army tireless and efficient (there probably was such a pill, but that pill was methamphetamine). In response, Roosevelt convened a 900–person National Nutrition Conference for Defense, a full quarter of them home economists, to tackle malnutrition as part of the war effort.

Maybe it’s not surprising that vitamins had such a hold on the popular imagination. It’s hard for us to imagine growing up in a world where scurvy, beriberi, and rickets were a real and even terrifying danger, not just funny-sounding words you might encounter in a Dickens novel. But for people living in the 1920s, they were no joke. Look at your local five-year-old and think how they will never understand the real importance of the internet, and what life was like before. You’re the same way about vitamins.

Milk

The final thing we learned is that people from the 1920s and 1930s had an intense, almost deranged love for milk.

Milk was always mentioned first and usually mentioned often. It was on every menu. Good Housekeeping’s 1926 article, Guide Posts to Balanced Meals, included “One pint of milk a day as either a beverage or partly in soups, sauces or desserts” as guidepost #1. Pamphlets from the USDA’s Bureau of Home Economics suggested that one fifth of a family’s food budget should be spent on milk. Milk was served at every meal in the schoolhouse, with milk and crackers at recess, the target being a quart of milk for every child, every day.

Milk was on every relief list. Food relief in NYC in 1930, a very strict beans-and-potatoes affair, still made sure to include a pound of evaporated milk for every family. Even for those on microscopic fifty-cent-a-day menus, milk was recommended at every meal, “one pint for breakfast, some for lunch, and then another pint for supper.” One father struggling to adjust to the Depression said, “We had trouble learning to live within the food allowance allotted us. We learned it meant oleomargarine instead of butter. It meant one quart of milk a day for the children instead of three.” Even the tightest-fisted relief lists included a pint of milk a day for adults, and a quart a day for children. The most restrictive diets of all were bread and — you guessed it — milk.

Milk was the measure of destitution. Descriptions of people eating “whatever they could get” sound like this: “inferior qualities of food and less of it; less milk; loose milk instead of bottled milk, coffee for children who previously drank milk.” When describing the plight of West Virginia mining families, a state union leader said, “Their diet is potatoes, bread, beans, oleomargarine, but not meat, except sow-belly two or three times a week. The company won’t let the miners keep cows or pigs and the children almost never have fresh milk. Only a few get even canned milk.”

There’s no question — milk was the best food. The government sent McCollum, the guy who discovered vitamins, around the country, where in his lectures he said:

Who are the peoples who have achieved, who have become large, strong, vigorous people, who have reduced their infant mortality, who have the best trades in the world, who have an appreciation for art and literature and music, who are progressive in science and every activity of the human intellect? They are the people who have patronized the dairy industry.

Normal milk wasn’t enough for these people, so in 1933 they developed a line of “wonder foods” around the idea of combining milk with different kinds of cereals. They called them: Milkorno, Milkwheato, and Milkoat. These products are about what you would expect, but the reception was feverish:  

With great fanfare, Rose introduced Milkorno, the first of the cereals, at Cornell’s February 1933 Farm & Home Week, where the assembled dignitaries—including Eleanor Roosevelt, wife of the president-elect—were fed a budget meal that included a Milkorno polenta with tomato sauce. The price tag per person was 6½ cents. FERA chose Milkwheato (manufactured under the Cornell Research Foundation’s patent) to add to its shipments of surplus foods, contracting with the Grange League Federation and the Ralston Purina Company to manufacture it. … Milkwheato and its sister cereals represented the pinnacle of scientifically enlightened eating. Forerunners to our own protein bars and nutritional shakes, they were high in nutrients, inexpensive, and nonperishable. White in color and with no pronounced flavor of their own, they were versatile too. Easily adapted to a variety of culinary applications, they boosted the nutritional value of whatever dish they touched. They could be baked into muffins, cookies, biscuits, and breads; stirred into chowders and chili con carne; mixed into meat loaf; and even used in place of noodles in Chinese chop suey.

We had always assumed that the American obsession with milk was the result of the dairy lobby trying to push more calcium on us than we really need. And maybe this is partially true. But public opinion of dairy has fallen so far from the rabid heights of the 1930s that now we wonder if milk might actually be underestimated. Is the dairy lobby asleep at the wheel? Still resting on their laurels? Anyways, if you want to eat the way your ancestors ate back in the 1920s, the authentic way to start your day off right is by drinking a nice tall pint of milk.

[1] : There might be a class element here? The authors say, “FDR recoiled from the plebeian food foisted on him as president; perhaps no dish was more off-putting to him than what home economists referred to as ‘salads,’ assemblages made from canned fruit, cream cheese, gelatin, and mayonnaise.”


PART II HERE

Investigation: Ultra-Processed Diets by Hall et al. (2019)

[This is Part One of a two-part analysis in collaboration with Nick Brown. Part Two is on Nick’s blog.]

I. 

Recently we came across a 2019 paper called Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake, by Kevin D. Hall and colleagues. 

Briefly, Hall et al. (2019) is a metabolic ward study on the effects of “ultra-processed” foods on energy intake and weight gain. The participants were 20 adults, an average of 31.2 years old. They had a mean BMI of 27, so on average participants were slightly overweight, but not obese.

Participants were admitted to the metabolic ward and randomly assigned to one of two conditions. They either ate an ultra-processed diet for two weeks, immediately followed by an unprocessed diet for two weeks — or they ate an unprocessed diet for two weeks, immediately followed by an ultra-processed diet for two weeks. The study was ad libitum, so whether they were eating an unprocessed or an ultra-processed diet, participants were always allowed to eat as much as they wanted — in the words of the authors, “subjects were instructed to consume as much or as little as desired.”

The authors found that people ate more on the ultra-processed diet and gained a small amount of weight, compared to the unprocessed diet, where they ate less and lost a small amount of weight.

We’re not in the habit of re-analyzing published papers, but we decided to take a closer look at this study because a couple of things in the abstract struck us as surprising. Weight change is one main outcome of interest for this study, and several unusual things about this measure stand out immediately. First, the two groups report the same amount of change in body weight, the only difference being that one group gained weight and the other group lost it. In the ultra-processed diet group, people gained 0.9 ± 0.3 kg (p = 0.009), and in the unprocessed diet group, people lost 0.9 ± 0.3 kg (p = 0.007). (Those ± values are standard errors of the mean.) It’s pretty unlikely for the means of both groups to be identical, and it’s very unlikely that both the means and the standard errors would be identical.

It’s not impossible for these numbers to be the same (and in fact, they are not precisely equal in the raw data, though they are still pretty close), especially given that they’re rounded to one decimal place. But it is weird. We ran some simple simulations which suggest that this should only happen about 5% of the time — but this is assuming that the means and SDs of the two groups are both identical in the population, which itself is very unlikely.

Another test of interest reported in the abstract also seemed odd. They report that weight changes were highly correlated with energy intake (r = 0.8, p < 0.0001). This correlation coefficient struck us as surprising, because it’s pretty huge. There are very few measures that are correlated with one another at 0.8 — these are the types of correlations we tend to see between identical twins, or repeated measurements of the same person. As an example, in identical twins, BMI is correlated at about r = 0.8, and height at about r = 0.9.

We know that these points are pretty ticky-tacky stuff. By themselves, they’re not much, but they bothered us. Something already seemed weird, and we hadn’t even gotten past the abstract.

Even the authors found these results surprising, and have said so on a couple of occasions. As a result, we decided to take a closer look. Fortunately for us, the authors have followed best practices and all their data is available on the OSF.

To conduct this analysis, we teamed up with Nick Brown, with additional help from James Heathers. We focused on one particular dependent variable of this study, weight change, while Nick took a broader look at several elements of the paper.

II. 

Because we were most interested in weight change, we decided to begin by taking a close look at the file “deltabw”. In mathematics, delta usually means “change” or “the change in”, and “bw” here stands for “body weight”, so this title indicates that the file contains data for the change in participants’ body weights. On the OSF this is in the form of a SAS .sas7bdat file, but we converted it to a .csv file, which is a little easier to work with.

Here’s a screenshot of what the deltabw file looks like:

In this spreadsheet, each row tells us about the weight for one participant on one day of the 4-week-long study. These daily body weight measurements were performed at 6am each morning, so we have one row for every day. 

Let’s also orient you to the columns. “StudyID” is the ID for each participant. Here we can see that in this screenshot we are looking just at participant ADL001, or participant 01 for short. The “Period” variable tells us whether the participant was eating an ultra-processed (PROC) or an unprocessed (UNPROC) diet on that day. Here we can see that participant 01 was part of the group who had an unprocessed diet for the first two weeks, before switching to the ultra-processed diet for the last two weeks. “Day” tells us which day in the 28-day study the measurement is from. Here we show only the first 20 days for participant 01. 

“BW” is the main variable of interest, as it is the participant’s measured weight, in kilograms, for that day of the study. “DayInPeriod” tells us which day they are on for that particular diet. Each participant goes 14 days on one diet then begins day 1 on the other diet. “BaseBW” is just their weight for day 1 on that period. Participant 01 was 94.87 kg on day one of the unprocessed diet, so this column holds that value as long as they’re on that diet. “DeltaBW” is the difference between their weight on that day and the weight they were at the beginning of that period. For example, participant 01 weighed 94.87 kg on day one and 94.07 kg on day nine, so the DeltaBW value for day nine is -0.80.

Finally, “DeltaDaily” is a variable that we added, which is just a simple calculation of how much the participant’s weight changed each day. If someone weighed 82.85 kg yesterday and they weigh 82.95 kg today, the DeltaDaily would be 0.10, because they gained 0.10 kg in the last 24 hours.

To begin with, we were able to replicate the authors’ main findings. When we don’t round to one decimal place, we see that participants on the ultra-processed diet gained an average of 0.9380 (± 0.3219) kg, and participants on the unprocessed diet lost an average of 0.9085 (± 0.3006) kg. That’s only a difference of 0.0295 kg in absolute values in the means, and 0.0213 kg for the standard errors, which we still find quite surprising. Note that this is different from the concern about standard errors raised by Drs. Mackerras and Blizzard. Many of the standard errors in this paper come from GLM analysis, which assumes homogeneity of variances and often leads to identical standard errors. But these are independently calculated standard errors of the mean for each condition, so it is still somewhat surprising that they are so similar (though not identical).  

On average these participants gained and lost impressive, but not shocking amounts of weight. A few of the participants, however, saw weight loss that was very concerning. One woman lost 4.3 kg in 14 days which, to quote Nick Brown, “is what I would expect if she had dysentery” (evocative though perhaps a little excessive). In fact, according to the data, she lost 2.39 kg in the first five days alone. We also notice that this patient was only 67.12 kg (about 148 lbs) to begin with, so such a huge loss is proportionally even more concerning. This is the most extreme case, of course, but not the only case of such intense weight change over such a short period.

The article tells us that participants were weighed on a Welch Allyn Scale-Tronix 5702 scale, which has a resolution of 0.1 lb or 100 grams (0.1 kg). This means it should only display data to one decimal place. Here’s the manufacturer’s specification sheet for that model. But participant weights in the file deltabw are all reported to two decimal places; that is, with a precision of 0.01 kg, as you can clearly see from the screenshot above. Of the 560 weight readings in the data file, only 55 end in zero. It is not clear how this is possible, since the scale apparently doesn’t display this much precision. 

To confirm this, we wrote to Welch Allyn’s customer support department, who confirmed that the model 5702 has 0.1 kg resolution.

We also considered the possibility that the researchers measured people’s weight in pounds and then converted to kilograms, in order to use the scale’s better precision of 0.1 pounds (45.4 grams) rather than 100 grams. However, in this case, one would expect to see that all of the changes in weight were multiples of (approximately) 0.045 kg, which is not what we observe.

III.

As we look closer at the numbers, things get even more confusing. 

As we noted, Hall et al. report participant weight to two decimal places in kilograms for every participant on every day. Kilograms to two decimal places should be pretty sensitive, but there are many cases where the exact same weight appears two or even three times in a row. For example, participant 21 is listed as having a weight of exactly 59.32 kg on days 12, 13, and 14, participant 13 is listed as having a weight of exactly 96.43 kg on days 10, 11, and 12, and participant 06 is listed as having a weight of exactly 49.54 kg on days 23, 24, and 25. 

Having the same weight for two or even three days in a row may not seem that strange, but it is very remarkable when the measurement is in kilograms precise to two decimal places. After all, 0.01 kg (10 grams) is not very much weight at all. A standard egg weighs about 0.05 kg (50 grams). A shot of liquor is a little less, usually a bit more than 0.03 kg (30 grams). A tablespoon of water is about 0.015 kg (15 grams). This suggests that people’s weights are varying by less than the weight of a tablespoon of water over the course of entire days, and sometimes over multiple days. This uncanny precision seems even more unusual when we note that body weight measurements were taken at 6 am every morning “after the first void”, which suggests that participants’ bodily functions were precise to 0.01 kg on certain days as well. 

The case of participant 06 is particularly confusing, as 49.54 kg is exactly one kilogram less, to two decimal places, than the baseline for this participant’s weight when they started, 50.54 kg. Furthermore, in the “unprocessed” period, participant 06 only ever seems to lose or gain weight in full increments of 0.10 kilograms. 

We see similar patterns in the data from other participants. Let’s take a look at the DeltaDaily variable. As a reminder, this variable is just the difference between a person’s weight on one day and the day before. These are nothing more than daily changes in weight. 

Because these numbers are calculated from the difference between two weight measurements, both of which are reported to two decimal places of accuracy, these numbers should have two places of accuracy as well. But surprisingly, we see that many of these weight changes are in full increments of 0.10.

Take a look at the histograms below. The top histogram is the distribution of weight changes by day. For example, a person might gain 0.10 kg between days 15 and 16, and that would be one of the observations in this histogram. 

You’ll see that these data have an extremely unnatural hair-comb pattern of spikes, with only a few observations in between. This is because the vast majority (~71%) of the weight changes are in exact multiples of 0.10, despite the fact that weights and weight changes are reported to two decimal places. That is to say, participants’ weights usually changed in increments like 0.20 kg, -0.10 kg, or 0.40 kg, and almost never in increments like -0.03 kg, 0.12 kg, or 0.28 kg. 

For comparison, on the bottom is a sample from a simulated normal distribution with identical n, mean, and standard deviation. You’ll see that there is no hair-comb pattern for these data.

As we mentioned earlier, there are several cases where a participant stays at the exact same weight for two or three days in a row. The distribution we see here is the cause. As you can see, the most common daily change is exactly zero. Now, it’s certainly possible to imagine why some values might end up being zero in a study like this. There might be a technical incident with the scale, a clerical error, or a mistake when recording handwritten data on the computer. A lazy lab assistant might lose their notes, resulting in the previous day’s value being used as the reasonable best estimate. But since a change of exactly zero is the modal response, a full 9% of all measurements, it’s hard to imagine that these are all omissions or technical errors.

In addition, there’s something very strange going on with the trailing digits:

On the top here we have the distribution of digits in the 0.1 place. For example, a measurement of 0.29 kg would appear as a 2 here. This follows about the distribution we would expect, though there are a few more 1’s and fewer 0’s than usual. 

The bottom histogram is where things get weird. Here we have the distribution of digits in the 0.01 place. For example, a measurement of 0.29 kg would appear as a 9 here. As you can see, 382/540 of these observations have a 0 in their 0.01’s place — this is the same as that figure of 71% of measured changes being in full increments of 0.10 kg that we mentioned earlier. 

The rest of the distribution is also very strange. When the trailing digit is not a zero, it is almost certainly a 1 or a 9, possibly a 2 or an 8, and almost never anything else. Of 540 observed weight changes, only 3 have a trailing digit of 5.

We can see that this is not what we would expect from (simulated) normally distributed data:

It’s also not what we would expect to see if they were measuring to one decimal place most of the time (~70%), but to two decimal places on occasion (~30%). As we’ve already mentioned, this doesn’t make sense from a methodological standpoint, because all daily weights are to two decimal places. But even it somehow were a measurement accuracy issue, we would expect an equal distribution across all the other digits besides zero, like this:

This is certainly not what we see in the reported data. The fact that 1 and 9 are the most likely trailing digit after 0, and that 2 and 8 are most likely after that, is especially strange.

IV. 

When we first started looking into this paper, we approached Retraction Watch, who said they considered it a potential story. After completing the analyses above, we shared an early version of this post with Retraction Watch, and with our permission they approached the authors for comment. The authors were kind enough to offer feedback on what we had found, and when we examined their explanation, we found that it clarified a number of our points of confusion. 

The first thing they shared with us was this erratum from October 2020, which we hadn’t seen before. The erratum reports that they noticed an error in the documented diet order of one participant. This is an important note but doesn’t affect the analyses we present here, which have very little to do with diet conditions.

Kevin Hall, the first author on this paper, also shared a clarification on how body weights were calculated:

I think I just discovered the likely explanation about the distribution of high-precision digits in the body weight measurements that are the main subject of one of the blogs. It’s kind of illustrative of how difficult it is to fully report experimental methods! It turns out that the body weight measurements were recorded to the 0.1 kg according to the scale precision. However, we subtracted the weight of the subject’s pajamas that were measured using a more precise balance at a single time point. We repeated subtracting the mass of the pajamas on all occasions when the subject wore those pajamas. See the example excerpted below from the original form from one subject who wore the same pajamas (PJs) for three days and then switched to a new set. Obviously, the repeating high precision digits are due to the constant PJs! 😉

This matches what is reported in the paper, where they state, “Subjects wore hospital-issued top and bottom pajamas which were pre-weighed and deducted from scale weight.” 

Kevin also included the following image, which shows part of how the data was recorded for one participant: 

If we understand this correctly, the first time a participant wore a set of pajamas, the pajamas were weighed to three decimals of precision. Then, that measurement was subtracted from the participant’s weight on the scale (“Patient Weight”) on every consecutive morning, to calculate the participant’s body weight. For an unclear reason, this was recorded to two decimals of precision, rather than the one decimal of precision given by the scale, or the three decimals of precision given by the PJ weights. When the participant switched to a new set of pajamas, the new set was weighed to three decimals of precision, and that number was used to calculate participant body weight until they switched to yet another new set of pajamas, etc.

We assume that the measurement for the pajamas is given in kilograms, even though they write “g” and “gm” (“qm”?) in the column. I wish my undergraduate lab TAs were as forgiving as the editors at Cell Metabolism.

This method does account for the fact that participant body weights were reported to two decimal places of precision, despite the fact that the scale only measures weight to one decimal place of precision. Even so, there were a couple of things that we still found confusing.

The variable that interests us the most is the DeltaDaily variable. We can easily calculate that variable for the provided example, like so:

We can see that whenever a participant doesn’t change their pajamas on consecutive days, there’s a trailing zero. In this way, the pajamas can account for the fact that 71% of the time, the trailing digits in the DeltaDaily variable were zeros. 

We also see that whenever the trailing digit is not zero, that lets us identify when a participant has changed their pajamas. Note of course that about ten percent of the time, a change in pajamas will also lead to a trailing digit of zero. So every trailing digit that isn’t zero is a pajama change, though a small number of the zeros will also be “hidden” pajama changes.

In any case, we can use this to make inferences about how often participants change their pajamas, which we find rather confusing. Participants often change their pajamas every day for multiple days in a row, or go long stretches without apparently changing their pajamas at all, and sometimes these are the same participants. It’s possible that these long stretches without any apparent change of pajamas are the result of the “hidden” changes we mentioned, because about 10% of the time changes would happen without the trailing digit changing, but it’s still surprising.

For example, participant 05 changes their pajamas on day 2, day 5, and day 10, and then apparently doesn’t change their pajamas again until day 28, going more than two weeks without a change in PJs. Participant 20, in contrast, changes pajamas at least 16 times over 28 days, including every day for the last four days of the study. The record for this, however, has to go to participant 03, who at one point appears to have switched pajamas every day for at least seven days in a row. Participant 03 then goes eight days in a row without changing pajamas before switching pajamas every day for three days in a row. 

Participant 08 (the participant from the image above) seems to change their pajamas only twice during the entire 28-day study, once on day 4 and again on day 28. Certainly this is possible, but it doesn’t look like the pajama-wearing habits we would expect. It’s true that some people probably want to change their pajamas more than others, but this doesn’t seem like it can be entirely attributed to personality, as some people don’t change pajamas at all for a long time, and then start to change them nearly every day, or vice-versa.

We were also unclear on whether the pajamas adjustment could account for the most confusing pattern we saw in the data for this article, the distribution of digits in the .01 place for the DeltaDaily variable:

The pajamas method can explain why there are so many zeros — any day a participant didn’t change their pajamas, there would be a zero, and it’s conceivable that participants only changed their pajamas on 30% of the days they were in the study. 

We weren’t sure if the pajamas method could explain the distribution of the other digits. For the trailing digits that aren’t zero, 42% of them are 1’s, 27% of them are 9’s, 9% of them are 2’s, 8% of them are 8’s, and the remaining digits account for only about 3% each. This seems very strange.

You’ll recall that the DeltaDaily values record the changes in participant weights between consecutive days. Because the weight of the scale is only precise to 0.1 kg, the data in the 0.01 place records information about the difference between two different pairs of pajamas. For illustration, in the example Kevin Hall provided, the participant switched between a pair of pajamas weighing 0.418 kg and a pair weighing 0.376 kg. These are different by 0.042 kg, so when they rounded it to two digits, the difference we see in the DeltaDaily has a trailing digit of 4. 

We wanted to know if the pajama adjustment could explain why the difference (for the digit in the 0.01’s place) between the weights of two pairs of pajamas are 14x more likely to be a 1 than a 6, or 9x more likely to be a 9 than a 3. 

Verbal arguments quickly got very confusing, so we decided to run some simulations. We simulated 20 participants, for 28 days each, just like the actual study. On day one, simulated participants were assigned a starting weight, which was a random integer between 40 and 100. Every day, their weight changed by an amount between -1.5 and 1.5 by increments of 0.1 (-1.5, -1.4, -1.3 … 1.4, 1.5), with each increment having an equal chance of occuring. 

The important part of the simulation were the pajamas, of course. Participants were assigned a pajama weight on day 1, and each day they had a 35% chance of changing pajamas, and being assigned a new pajama weight. The real question was how to generate a reasonable distribution of pajama weights. We didn’t have much to go off of, just the two values in the image that Kevin Hall shared with us. But we decided to give it a shot with just that information. Weights of 418 g and 376 g have a mean of just under 400 g and a standard deviation of 30 g, so we decided to sample our pajama weights from a normal distribution with those parameters.

When we ran this simulation, we found a distribution of digits in the 0.01 place that didn’t show the same saddle-shaped distribution as in the data from the paper:

We decided to run some additional simulations, just to be sure. To our surprise, when the SD of the pajamas is smaller, in the range of 10-20 g, you can sometimes get saddle-shaped distributions just like the ones we saw in data from the paper. Here’s an example of what the digits can look like when the SD of the pajamas is 15 g:

It’s hard for us to say whether a standard deviation of 15 g or of 30 g is more realistic for hospital pajamas, but it’s clear that under certain circumstances, pajama adjustments can create this kind of distribution (we propose calling it the “pajama distribution”).

While we find this distribution surprising, we conclude that it is possible given what we know about these data and how the weights were calculated.

V. 

When we took a close look at these data, we originally found a number of patterns that we were unable to explain. Having communicated with the authors, we now think that while there are some strange choices in their analysis, most of these patterns can be explained when we take into account the fact that pajama weights were deducted from scale weights, and the two weights had different levels of precision.

While these patterns can be explained by the pajama adjustment described by Kevin Hall, there are some important lessons here. The first, as Kevin notes in his comment, is that it can be very difficult to fully record one’s methods. It would have been better to include the full history of this variable in the data files, including the pajama weights, instead of recording the weights and performing the relevant comparisons by hand. 

The second is a lesson about combining data of different levels of precision. The hair-comb pattern that we observed in the distribution of DeltaDaily scores was truly bizarre, and was reason for serious concern. It turns out that this kind of distribution can occur when a measure with one decimal of precision is combined with another measure with three decimals of precision, with the result being rounded to two decimals of precision. In the future researchers should try to avoid combining data in this way to avoid creating such artifacts. While it may not affect their conclusions, it is strange for the authors to claim that someone’s weight changed by (for example) 1.27 kg, when they have no way to measure the change to that level of precision.

There are some more minor points that this explanation does not address, however. We still find it surprising how consistent the weight change was in this study, and how extreme some of the weight changes were. We also remain somewhat confused by how often participants changed (or didn’t change) their pajamas. 

This post continues in Part Two over at Nick Brown’s blog, where he covers several other aspects of the study design and data.

Thanks again to Nick Brown for comparing notes with us on this analysis, to James Heathers for helpful comments, and to a couple of early readers who asked to remain anonymous. Special thanks to Kevin Hall and the other authors of the original paper, who have been extremely forthcoming and polite in their correspondence. We look forward to ongoing public discussion of these analyses, as we believe the open exchange of ideas can benefit the scientific community.