In the beginning, scientific articles were just letters. Eventually Henry Oldenburg started pulling some of these letters together and printing them as the Philosophical Transactions of the Royal Society, the first scientific journal. In continuance of this hallowed tradition, here at SLIME MOLD TIME MOLD we occasionally publish our own correspondence as a new generation of philosophical transactions.

Today’s correspondence is from a husband and wife who wish to remain anonymous. This account has been lightly edited for clarity, but what appears below is otherwise the original report as we received it. 

The potato diet has mostly been used for weight loss, but it’s also notable for involving mostly one food and being close to nutritionally complete, which means you can use it as an elimination diet to study things like food triggers. We’ve been interested in this idea for a long time, and we find this case study particularly compelling because it’s a rare example of someone doing just that!

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Since around 2018, K had been suffering from stomach pain, bloating, gas, and chronic constipation. Chronic constipation worsened after two pregnancies, so K sought medical intervention again in Feb 2025. K was prescribed medication (Linzess) to treat the constipation, which initially improved symptoms but was unreliable and had unpleasant side effects. She had been on that medication for 1 month before starting the potato diet.

Family and friends were bewildered to hear our plan, warning us of muscle loss and blood sugar problems since potatoes are ‘bad’.

Her initial goal was to lose 5-10 pounds from a starting BMI of 23.4 and test out the claims we read online about the diet. K actually joked, “wouldn’t it be funny if this diet fixes my stomach problems?”

We started the diet on 21MAR2025. The first two and a half days were 100% potato for both of us. Morale was suffering by the afternoon of day 3, so we caved and had a potato-heavy dinner with our kids. Afterwards, we agreed to eat only potatoes until dinner so we could still have a normal family meal time. We did make sure potatoes featured heavily in the weekly meal plan.

Within a week, K noticed improved symptoms and regularity without any medication. Initially, she thought she might have a lactose intolerance, so she switched to lactose-free milk and quit the potato diet once we reached the end of our planned testing window.

Back on a regular diet (but still avoiding lactose), K’s symptoms came back worse, with constant stomach aches and bloating. K realized that she had unintentionally been on a low-FODMAP diet while on the potato diet and decided to do intolerance testing. 

Her methodology for intolerance testing follows:

1. Ate a high-potato, low FODMAP diet until minimal symptoms were present.
2. Used NHS FODMAP rechallenging protocol to isolate FODMAP groups (lactose, fructans from wheat, fructans from onions, fructans from garlic, fructans from fruit, fructose, galactooligosaccharides, sorbitol, mannitol, fructose + sorbitol) and identify foods to use for testing each group
3. Spent 3 days of rechallenging per group: day 1 – small portion, day 2 – med portion, day 3 – large portion of challenge food (ex: 1/4 cup milk, 1/2 cup milk, 1 cup milk)
4. Kept daily log of symptoms and severity
5. Allowed 3 days of ‘washout’ after rechallenging
6. Rechallenged next food group, but did not incorporate challenged foods into diet to avoid multiple FODMAP effects
7. If symptoms appeared after a food challenge, waited till symptoms subsided and repeated the rechallenge over another 3 days

Incorporating lots of potatoes allowed K to test out food groups while still eating a well-balanced diet. The culprit for K is fructans from wheat, which is why cutting out daily servings of wheat has made her symptoms disappear.

K is finishing FODMAP testing (still a couple more groups to go), but has had reliable relief from all symptoms without any meds. Potatoes are a regular addition to meals these days. 

Below is the blank version of the log she used.