The Potato Diet Version of the Fasting Mimicking Diet

Last week I completed my second Fasting Mimicking Diet. Well kind of. It was my own variation of the diet inspired by Marc’s comment on this blog.

Background info here:

A true FMD actually restricts carbohydrates as well as protein. The case for restricting carbs during the 5 days didn’t seem nearly as strong as the case for restricting protein, so I used my favorite food tool, which is the boiled potato to help me through the 5 days.

Unlike the first FMD, I did not outright fast for the first 3 days. I wanted to experience the diet with the low level of calories while restricting protein. Using boiled potatoes and butter, I was able to keep my protein under 20 grams each day. 20 grams is a very conservative estimate I got from the 2011 Protein Cycling Diet book. (It is for a person weighing 154 and I weight 198)

The upside of using boiled potatoes instead of the menu ideas in the FMD book is that the potato has high volume and will limit hunger better than other foods. Plus potatoes are cheap and easy to prepare.

Dr. Longo’s menus are easy enough to assemble, but when you are running on low calories, who wants to prep food in that manner? That is probably why the ProLon company exists. Cooking isn’t hard, but keeping the dieter out of the kitchen as much as possible is likely half the battle.


I was a little more active during this FMD. My daily steps averaged 8,000 and I did some light yoga and stretching.


As to be expected, I lost less weight than my first FMD when I fasted 3 days.

  • Day 0: 198  (morning before Day 1)
  • Day 6: 194   (morning after the end of FMD)
  • Day 9: 196.5 (weekend after FMD)

I did not get light-headed or cold this time, which makes sense, given both the warmer weather and more calories.

I do have more thoughts on the Fasting Mimicking Diet and Dr. Longo’s book in general, which I will put in a separate post. But my general take away experience is that this form of fasting will be doable for many people that could not fathom missing a single meal.

seattle street art

I took this photo last month. It has nothing to do with this post. 

JULY 2018 UPDATE: Insulin may affect IGF-1 in ways I do not understand, so I am backing away from the Potato version of the FMD for now.


Add yours

  1. Good job. Back in 2011/2012, I fasted every week, eating dinner on Wednesday and nothing until lunch on Friday, essentially skipping two meals in a 42 hour fasted state. During that time, I’d sometimes lose up to 6 or 8 pounds, all of which would be gained back over the weekend. After a year of this, I had nothing to show for it in the way of body comp or fat, remaining about 15-20% body fat the whole time. I certainly did not get super-lean like I hoped.

    I keep thinking I need to start doing this again, but I’ve kind of lost the desire to fast for more than 18 hours at a stretch. I might give your potato fast a try, though.

    I still think someone could make a fortune selling “People Chow” in 50 pound bags like dog food. It would need to be crunchy and you could add hot water for more of a meal. I would love to be able to dole out a measured amount of calories knowing it meets all my nutrition goals, and not have to worry about every little thing I eat (sounds a lot like the potato hack, lol).

    Did you read up much on the Soylent deal? [ ] Same kind of thing, but Soylent gets very poor reviews and quite expensive.

  2. Thanks for the info mas. You feel good too? If weight loss was the only goal, and I apologise if this has been covered years ago, would you consider a 4:3 or 5:2 protocol using potatoes to make up the 500 to 600 cals on fast days?

    Tim, good idea with the chow. I’ve read a few bits and pieces now where successful followers of leangains base their whole days around a high protein cereal (kashi? We don’t have that in Australia), clearly labeled nutrition for calories and macros and all that noise, takes the guesswork out!

  3. @All – My motivation for the FMD was not for weight loss, but to get the recovery benefits from depriving the body of amino acids for 5 days. Primarily, the spike in stem cell production. My *hope* is that this will increase the speed of recovery I have for both injuries and exercise. This may be a false hope, as I don’t have metrics to measure anything. The upside benefits spelled out in Longo’s book and the Protein Cycling Diet are also of interest.

    As for fat loss, I listed 12 things that worked better for me than IF here:

    During the 25 days of the month when I am not doing the FMD, my protein levels will be higher. Spike and reset. Rinse and repeat.

  4. Thanks for keeping Do-It-Yourself FMD’s in the spotlight. I found that drinking salt water (0.5 teaspoon salt per 2 liters) helped me during my DIY FMD’s; my Eustachian tubes felt funny until the salt water helped my tissues hold onto some water. Anyone else drinking salt water and/or getting electrolytes some other way?

    Like MAS, I also think and hope that increasing the complex carbs to replace some fat during FMD will not change the beneficial results. My fat during FMD comes from olive oil and avocado, not butter.

  5. Yes, I also drank salt water. More on the pure fasts than this time, since I was getting plenty of salt on my potatoes.

  6. I’m going to give the potato FMD a try after Easter. Spike in stem cells would be great, but I’m wondering if 5 days of potatoes might potentially work as a food reward “reset” of sorts. That could be handy if so!

  7. @All – I should have been more clear in the post. With the Potato FMD, you do need to restrict the potatoes you eat. Otherwise, you will overshoot the protein, which defeats the purpose.

    Figure out your protein levels. For a 154 pounds, it is 20 grams a day. Go from there. I kept my number in the 12-15 gram range during my Potato FMD at a weight of 198. Very conservative.

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