Potato diet comparisons

To my knowledge, no one has yet undertaken a thorough comparison of the various potato diets that have been organized by Slime Mold Time Mold. I, too, did not set off with such a goal, but I have arrived with such a result, which I now present to you!

To start, let’s directly compare the results of the potato diets, as presented by Slime Mold Time Mold in their post-diet analyses:

The potassium trial and half-potato diets were both run for 28 days, but the original potato diet was only run for 27 days. To more fairly compare the diets, let’s pretend that the potato diet was also run for 28 days by multiplying the total weight loss by 28/27.

In the potato riffs experiment, different people dieted for different numbers of days, so in order to more accurately compare the potato riffs with the other diets, let’s drop any data that was recorded after day 28 and normalize the data for anyone who participated for fewer than 28 days.

Making these changes yields slightly different results:

People tend to lose a large amount of weight during the first week of a new diet, and then the weight loss levels off. For example, in the original potato diet, people lost an average of 11.0lb over four weeks, but almost half of that weight was lost during the first week:

This seems to apply to the other diets, too:

One of the effects of this is that shorter diets incorrectly appear to work better. For example, here’s what the average weight loss per week would have been if the original potato diet had ended after one week, two weeks, three weeks, or four weeks:

The easiest way to fix this is to drop the first week of data from each diet and compare the average weekly weight loss for the rest of the diet:

Dropping the first week of data from a diet also has a couple of other advantages:

• There’s less need for people to establish a baseline weight before starting a diet.
• People get a better sense of how much fat might be lost on a weekly basis, since inflated weight loss during the first week is probably due to water loss.

Now that we can fairly compare diets of different lengths, let’s add in the results of people who did the half-potato diet for eight weeks:

Let’s also separately track potato riff diets that were based around the concepts of adding dairy or meat to potatoes:

There are three potato riff diets that don’t seem to fit with the rest: Two people did normal potato diets (100% potato) and one person did a whole foods + chocolate diet. Let’s remove the whole foods + chocolate diet and move the two normal potato diets to the “potato diet” category:

Since heavier people tend to lose more weight when dieting, let’s also compare the diet based off of the percentage of total body weight that was lost:

I think that’s as good of a comparison as we’re going to get, so let’s order the table by effectiveness and look at the results!

The original potato diet is still king, but potatoes + dairy is a close second!

Potatoes + meat doesn’t seem to work nearly so well as 100% potatoes or potatoes + dairy, but some argue that a potato diet without substantial protein (e.g. 100% potatoes or potatoes + dairy) causes people to lose not only fat but also muscle. If this is true, then perhaps people doing potatoes + meat lose only fat, conserving their muscle, and therefore lose less weight.

Eating potatoes 50% of the time appears to be substantially less effective than eating potatoes 100% of the time but still might be a decent option for people who don’t mind losing weight slowly and can’t or don’t want to do a 100% potato diet.

People only lost 0.12lb per week by supplementing potassium. This isn’t much, but 0.12lb per week translates to 11lb a year, so while this might not be a great way to diet, it might be a good way to keep weight off. The question, I think, is whether supplementing potassium would continue to result in weight loss for more than a few weeks. At 0.12lb per week, I think there’s a real risk that the weight that people lost during the potassium trial was from shedding water, in which case supplementing potassium for a year probably wouldn’t help with weight loss at all. Directly supplementing potassium also comes with risks (see the next paragraph). Personally, I think it’d be really interesting to run a study where instead of directly supplementing potassium, people replace their normal salt with “light” salt (half sodium and half potassium) for a year and see if they lose any weight.

Anyone considering supplementing potassium should be very careful, as supplementing too much potassium is a good way to end up with death via heart failure. See Slime Mold Time Mold’s potassium trial instructions for more details.

For anyone considering trying out a potato diet, keep in mind that some people aren’t able to handle eating a bunch of potatoes (especially people with kidney issues). You also shouldn’t eat green potatoes, uncooked potatoes, etc. See the “Health” section of Slime Mold Time Mold’s potato diet results article for more details.

There’s probably lots more analysis that could be done, but that’s enough for me! :)

I hope these comparisons are useful, and I also hope that some thought can be given to the idea that dropping the first week of a diet’s data avoid the need for people to establish a baseline weight and makes for more fair comparisons.

Thank you to Slime Mold Time Mold for all of the work that they’ve done! ^_^