Potato Diet Riff Trial: Sign Up Now, Lol

When we finished the Potato Diet Community Trial, we found ourselves in a pickle. The diet worked — people lost 10.6 lbs on average over only four weeks — and we had basically no idea why. No idea what parts of the protocol were essential, and what parts were optional. 

We had no idea what would make it work better. We had no idea what might make it work worse. And we had no idea of the boundary conditions. We told everyone to avoid dairy, but was that really necessary? Is the potato diet very strict, and you need to stick closely to the original protocol? Or is it very lax? When does it stop working, and why? 

Since then, we have investigated a few of these questions. We tested our main hypothesis about the mechanism (potatoes give you high doses of potassium) and the results provided some support for that hypothesis. We tried a 50% potato AKA half-tato diet based on some case studies, but the results were underwhelming. And we’ve encouraged people to do self-experiments that try to get at the same questions. One example is friend-of-the-blog Krinn, who tried higher doses of potassium and consistently lost weight.

We could keep going like this, running one study at a time. But honestly, that would take forever. The problem is that you can easily come up with 100 different hypotheses for what’s going on. Ok, so you run 100 different studies to test each one. But studies take a long time to run — let’s say 6 months per study. Congratulations, you’ve just locked yourself into 50 years of studying nothing but iterations on the potato diet. There has to be a better way. 

So today we’re introducing a new kind of study we call the riff trial. Let’s see how it works!

Variations on a Meme

In a normal study, everyone follows pretty much the same protocol. In some kinds of studies, like randomized controlled trials, participants are randomly assigned to a small number of very similar protocols.

Instead of making protocols standard, the riff trial makes protocols different. In a riff trial, you start with a base protocol, and every participant follows a different variation. Everyone tests their own riff on the original protocol, and you see what happens. 

To give credit where credit is due, the blogger known as ExFatLoss did something like this first. He ran a study where 10 people signed up to try his ex150 protocol. In practice, however, most people tried minor riffs on the original protocol, like adding an “illegal” carrot salad, and they still generally lost weight. This is a better test of the robustness of his protocol, and it’s a more efficient way to explore the design space. 

Now it’s our turn. Today we are starting a Potato Riffs Trial, and we’re looking for people who want to try their own riff on the potato diet. 

A riff trial takes advantage of the power of parallel search. Some riffs will work better than others (or at least differently), and parallel search helps you find these differences faster, especially if the differences are big.

Or if you prefer, it uses the power of evolution. The original protocol goes out with mutations and we see how they do in the face of natural selection. If you want, you can even run a second riff trial on the most successful riff(s), to explore the space even further. In this way, the riff trial is the atomic gardening of study design.

Some riffs will be more compelling than others. If you do a riff and lose weight on that version of the potato diet, this suggests the potato diet is robust to that difference. If you do a riff and don’t lose weight, that’s tricker, because we know the potato diet doesn’t work for some people — maybe you are just one of those people. 

But even when individual riffs don’t prove much, together they can be suggestive. If ten people try potatoes + bacon and they all gain weight, that’s pretty strong evidence that bacon is the anti-potato. You could also account for this by doing a few weeks of the original potato diet to demonstrate that it works for you under normal conditions, and then starting the riff to see if anything changes.

A riff trial is scientific fun for friends and family. If a husband and wife living in the same house try different potato riffs, and have different results, we know the differences aren’t a result of their environment, since they live in the same house and sleep in the same bed and so on. If adult siblings living in different cities try the same potato riff and have different results, the differences are probably due to differences in their cities, since the siblings are closely related and are doing the same protocol.

This is also a way to put your money where your mouth is, so to speak. We love all y’all people on the internet, but some of you talk a lot and experiment very little. Science needs to be more competitive — not in the sense of arguing (bleh!) but in the sense of people actually doing studies to go after their disagreements rather than just theorizing about them. This is your chance to get your hands dirty.

And as always, this is a chance to PLAY with your ideas, to PLAY WITH SCIENCE, to JOIN the INTERNET HIVE MIND and MESS AROUND WITH YOUR FRIENDS. This can be your way to help welcome the 21st century scientific revolution you so desperately crave.

Tl;dr, we’re looking for people to volunteer to eat almost nothing but potatoes (depending on your riff) for at least four weeks, and to share their results. You can sign up below. For more detail, read on! 

Potato Riffs

As a reminder, here is our version of THE POTATO DIET (more detail can be found in the original post):

• Drink mostly water. You can also have other beverages like tea or coffee. Just don’t take them with cream or sugar and try not to get too many calories from your drinks. 
• Eat potatoes. 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. Do what you can to keep yourself from getting bored.
• Oil is ok.
• 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. 

Your mission, should you choose to accept it, is to try the potato diet plus some kind of variation of your choice for at least four weeks. You can try any riff you like, but for inspiration, here is a list of ideas:

• Whole foods
  • Potatoes + Avocado
  • Potatoes + Bananas
  • Potatoes + Cashews
  • Potatoes + Fruits
  • Potatoes + Leafy Greens
• Unwhole/Processed Foods
  • Potatoes + Snickers
  • Potatoes + Hot Dogs
  • Potatoes + Soda
  • Potatoes + 10% Ultra-Processed Foods
• Various Fats
  • Potatoes + Butter
  • Potatoes + Olive Oil
  • Potatoes + Sunflower Oil
• Grains
  • Potatoes + Bread
  • Potatoes + Rice
• Protein
  • Potatoes + Tofu
  • Potatoes + Chickpeas
  • Potatoes + Beans
  • Potatoes + Eggs
  • Potatoes + Ground Beef
  • Potatoes + Chicken
• Food Suspects
  • Potatoes + White Sugar
  • Potatoes + Honey
  • Potatoes + Chocolate
  • Potatoes + Cream
  • Potatoes + All Dairy
  • Potatoes + Ketchup
  • Potatoes + Tomato Sauce
• Preparation
  • Potatoes (baked only)
  • Potatoes (boiled only)
  • Potatoes (roasted only)
  • Potato Soup SOUP ONLY
• For Humor Only
  • Potatoes + Molasses

Before you sign up, let’s highlight some riffs we might be especially interested in:

Mono-Diet

Some people think the potato diet causes weight loss because it is a mono diet, a diet where you eat mostly one food. We think this is wrong! If it were true, 1) any other mono diet would also work, and 2) the half-tato diet wouldn’t work because you eat more than one thing. But the half-tato diet does seem to work, at least for some people. Also there was so much cheating in the original potato diet (by design!) that we’re not sure even most of those would could as a mono diet really:

So one very simple riff you can do is the potato diet plus some other food of your choice. Potatoes and apples. Potatoes and lettuce. Potatoes and carrots. If the mono-diet hypothesis is true, adding these other foods should stop the potato diet from working. If it keeps working, that’s a major problem for the mono-ness hypothesis. 

Deliciousness

Some people think the potato diet causes weight loss because it is bland. We think this is wrong too. First of all, potatoes are delicious. Second of all, this doesn’t make any sense. Why would that happen.

However, one riff you could do is potatoes plus one or two foods you think are especially delicious. This seems like a good deal. You get to eat potatoes and one or more of your favorite foods, as much as you want for a whole month, and you might lose weight for your trouble. If you do lose weight eating potatoes and a favorite food, that’s a major problem for the blandness hypothesis. Also it makes sense.

Potatoes + Whole Foods or Unwhole Foods

Some people think the potato diet causes weight loss because potatoes are whole foods — they are totally unprocessed, unadulterated, torn directly from the bosom of Mother Earth. This might be part of it, though it makes us wonder what it might be about “whole foods” that would make them cause weight loss. 

Anyways, one way to test this would be to try eating potatoes plus some other whole food, like almonds or bananas. If the whole food hypothesis is correct, this should cause as much weight loss as the normal potato diet, maybe more.

Or you could do the opposite, and try eating potatoes plus some highly-processed food, like snickers bars or Big Macs. If the whole food hypothesis is correct, eating these processed foods should make the potato diet much less effective. But if you lose weight on potatoes + gummy worms, that’s evidence against the whole foods hypothesis.

Potatoes + Cream

ExFatLoss has lost a lot of weight on a diet that is mostly heavy cream. When he recruited ten other people to try the same thing, most of them lost weight too. If potatoes cause weight loss, and cream causes weight loss, maybe potatoes and cream together will cause even more weight loss? 

Worth trying, at least, especially since in the original Potato Diet Community Trial, we asked people to avoid dairy. Maybe that was the wrong move. You could also do potatoes + light cream or potatoes + milk, to see if milkfat matters. Or just a general potatoes + dairy, where you eat both potatoes and any dairy products ad libitum. 

Potatoes + Various Fats

Some people think that seed oils are the cause of the obesity epidemic, and/or are bad for you in general. From this perspective, the reason the potato diet works is that it cuts all the seed oils out of your diet — you’re too busy eating potatoes. As we’ve previously argued, we don’t find this theory very convincing. But it’s easy enough to test. We wrote:

It would be easy to run a variation of the potato diet where half the participants are randomly assigned to eat their potatoes with butter, and the other half are randomly assigned to eat their potatoes with sunflower oil. (Or substitute these for whatever fats the seed oil theorists think are best and worst.) If the seed oil theory is correct, then the participants eating potatoes + butter should lose weight much faster than the participants eating potatoes + sunflower oil. If the seed oil theory is wrong, there should be basically no difference.

This would be a good subject for riff trials. If they want to, some people can sign up to eat olive oil with all their potatoes, some can sign up to eat butter with all their potatoes, some can sign up to eat canola oil, etc. Then we can see if there are big differences between people who choose different fats. 

If seed oil theorists are really confident in their theory, they should sign up and demonstrate that seed oils kill the potato weight loss effect, and other fats don’t.

Potatoes and Suspected Blockers

The potato diet may work by adding things to your diet, like huge doses of potassium. But it may also work by removing things from your diet. (It might also do both.) This suggests that there may be some foods that “block” the potato weight loss effect. You can test this in a riff by trying the potato diet plus one of these foods, to see if it keeps working or not.

One prime suspect is tomato and tomato products like ketchup. Ketchup came to our attention as a result of some anecdotes from the original Potato Diet Community Trial, stories where people felt that eating ketchup kept them from losing weight. As Jack Peterson noted, tomatoes blocking the effect “would explain why no one ever noticed [the weight loss properties of potatoes] prior to Chris Voigt’s stunt: because potatoes are usually eaten with ketchup”. And we were surprised to see that in the Half-Tato Diet Community Trial, weight loss was correlated with tomato consumption, r(36)=0.37, p=.021 (also significant when removing the extreme outlier, r(35)=0.36, p=.031). Plot here:  

So you could try a potato diet with ketchup in particular, or with tomato products in general. If you still lose weight, that would show that tomato isn’t necessarily a blocker. If you don’t lose weight, that’s pretty interesting. You could also try alternating weeks with and without tomatoes, to see if you can make the effect turn on and off at whim. Whee! 

Tomatoes are our top bet, but other possible blockers might be: wheat, bread, grains more generally, maybe meat. Carbs stand out because on the potato diet you are getting a lot of carbs. So even if you do take a cheat day, you probably won’t be cheating with bread, because you probably won’t crave that. Some people think sugar might be a blocker, so you could try potatoes + white sugar (but maybe not together, ew). Eggs or goji berries might also be blockers because they seem to be high in lithium. So one kind of riff would be trying potatoes and one of these foods and seeing how it goes. 

Potatoes + Chocolate

CuoreDiVetro recently published a self-experiment where they followed a very simple form of the potato diet, replacing one meal per day with a meal of just potatoes, supplemented by additional doses of potassium chloride (based off of a potassium:sodium ratio hypothesis that has been floating around). This worked very well for them at first — then they discovered that it appeared to work even better when they included chocolate, like so:

I bought dark baking chocolate (100% cacao) with a high concentration of potassium (just in case it was the potassium). I made my hot cacao by melting ~36g of dark chocolate (containing roughly 750 mg of K) in roughly one cup (250ml) of milk (containing roughly 350 mg of K) and sweetening it to taste. 

According to CuoreDiVetro, they lost weight four times faster when they were eating one hot chocolate per day in addition to their meal of potatoes.

This could be something about chocolate in particular. But it might also be yet another pointer to stearic acid, a waxy fat common in foods like tallow, lard, butterfat, and cocoa butter, which for some reason keeps showing up in weight loss research. If you’ve heard of this fat before, it’s likely from Fire in a Bottle (FIAB), a website/program/theory which argues that a diet high in stearic acid can cause weight loss. This is sometimes called The Croissant Diet (TCD), presumably in the hopes of confusing readers — you do not actually eat nothing but croissants. In fact, you don’t have to eat any croissants at all. But you do ideally eat lots of foods high in stearic acid, sometimes supplementing with additional stearic acid, and some people seem to lose weight when they do this.

There are other reasons to think that stearic acid might be involved. ExFatLoss and co must be getting a lot of stearic acid from the huge quantities of milkfat they’re consuming. And Outlier 17 from our Half-Tato Diet Community Trial, who lost way more weight than anyone else in the trial, often took straight stearic acid as a supplement. 

So you could supplement stearic acid on top of your potatoes and see what that does. Or you could try potato + chocolate, which seems more delicious. But to each their own. 

You could also try CuoreDiVetro’s riff exactly, or riff further off that riff. It appears to be 1) one meal per day as a meal of just potatoes, 2) potatoes are salted with 3.2 g KCl, 3) avoid adding NaCl (normal table salt) to potatoes, 4) at least one hot cacao per day, per the recipe above, and 5) otherwise eat as normal. This is really several riffs away from the main protocol and might not be as illuminating, but would give another similar data point for comparison. 

Preparation

We think the potato diet might cause weight loss because of the super high doses of potassium you get when you eat tons of potatoes. We also hear that boiling potatoes removes a lot of their potassium, because it drains out of the potato and into the boiling water. If this is the case, then eating nothing but boiled potatoes would probably cause much less weight loss than eating nothing but baked or roasted potatoes, which should still have all their potassium. Unless you boiled your potatoes as a soup and then drank all the broth.

Doing a riff where you only ate one kind of preparation, whether those be boiled, baked, fried, steamed, roasted, mashed, or souped potatoes, might illuminate this question. But it might be kind of boring.

Half-Tato Accelerator

Many people lose weight on the half-tato diet, like M, Nicky Case, Outlier 17, and CuoreDiVetro. We say “half-tato”, even though many of these people were getting less than 50% of their food from potatoes. But when we ran a community trial of the half-tato diet, most people barely lost any weight.

What gives? Maybe there’s some extra step required to make half-tato work. If we could figure out that extra step, people could lose weight with much less hassle. So if your riff seems to be working on full-tato, you could switch to half-tato and see if it keeps working just as well. Or you could try various riffs on half-tato and see if any of them serve as the switch. 

Get Confused

They say that the most exciting phrase to hear in science is not “Eureka!” but “That’s funny…” So the best thing that could happen would be if you find something really weird. For example, it would be very weird if people found that taking iron supplements makes the potato diet totally ineffective… unless you take iron supplements AND magnesium supplements, in which case it starts working again (we have no reason to think this would happen, just a wild hypothetical). If that happened and it were robust, it would be very surprising, and trying to puzzle it out would get us closer to an answer.

So if you have some other weird potato diet riff you want to try for some reason — we say, go for it!

Sign Up

Ok researchers, time to sign up.

The only prerequisites for signing up are: 

• You must be 18 or older;
• In generally good health, and specifically with no kidney problems;
• Willing to do some version of the potato diet, as described above, for at least four weeks, and;
• Willing to share your data with us — you can publish it as a philosophical transactions post on our blog if you like, or publish it somewhere else on your own.

As usual, you can sign up to lose weight, lower your blood pressure, get more energy, or see one of the other potential effects. But you can also sign up to help advance the state of medical science. This study will hopefully get us much closer to understanding why the potato diet causes weight loss. It might lead to a practical weight-loss intervention that’s much easier than the 100% potato diet, and it might lead to curing obesity for good.

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.

Eating this much potato may sound a little daunting, but people who have tried it say that it is much easier than they expected, and delicious to boot. Here’s our suggestion: If you are at all interested in trying a potato diet riff, go ahead and sign up and start collecting your data. Collect your baseline measurements for two weeks, then try the first day or two of the potato diet and see how it feels. If you hate it and have to stop, we would still love to have that 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.

We are mostly interested in weight loss effects for people who are overweight (BMI 25+) or obese (BMI 30+), but if you are “normal weight” (BMI 20-25) you can also sign up. 

And for everyone, please consult with your doctor before trying this or any other weight loss regimen. 

We realize that anyone who starts a potato riff soon will overlap with Thanksgiving and/or Christmas. So you’re welcome to wait and sign up later, we will keep signups open at least through January, maybe longer. But also, it’s not a problem if you overlap with the holidays, and it might be a good way to see how robust your riff is. Someone doing an “I ate potatoes and whatever holiday treats I wanted” would honestly be an amazing study.

In general, signups will be open for a while, and it’s all rolling signups. Pick out a riff and join whenever.

If you were part of previous SMTM studies, please feel free to sign up for this study as well! Just mention it, and provide any previous subject numbers, when you’re signing up.

How do you decide what riff to choose? Here are three approaches to consider:

1. Follow what you like. Do you like steak a lot? Maybe that’s a sign that your body needs more steak. Even if not, you would probably enjoy it. So why not sign up for a steak and potatoes riff? You might lose weight, and even if you don’t, you’ll be making an important scientific contribution while eating delicious foods you enjoy. 
2. Put your money where your mouth is. This is a chance to test your theoretical bone to pick, whatever that might be. If you think the potato diet works because it is low sugar, then potatoes + sugar shouldn’t work. You can try that and test your idea. If you think the potato diet works because it is a seed oil elimination diet, then potatoes + sunflower oil shouldn’t work, while potatoes + coconut oil should work as normal. You can recruit three friends and test it. You might be surprised. 
3. You can choose “randomly”. What sounds funny? What is no one else doing? Go with that. 

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. You will also tell us what riff(s) you’re interested in. 
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 whatever, just keep it consistent. Note down your weight and the other measures (mood, energy, etc.) on the google sheet.
4. Do your version of the potato diet for at least four weeks.
5. When you reach the end of the diet (whether you’re ending the diet early, reaching the end of 4 weeks, or reaching the end of a longer span), send us an email. Let us know if you want to publish your results yourself (in which case send us a link to your post) or if you want to publish your results on SMTM as a philosophical transactions post (in which case send us a detailed email about your protocol, results, and thoughts).
6. Remember that it is ok to end the study early if you need to, for example if you get sick. It’s also fine to reach the end of 4 weeks and keep going if you’re having a good time. Just make your intentions clear in the comments on your data sheet and send us an email whenever you decide to finish, we’d love to hear from you.

We plan for this to be somewhat more relaxed and more casual than our previous studies, so please understand if we take a few days to sign you up or get back to you about anything.

As always, if you think this is an interesting idea, please tell your friends!