[Taikonerd]

I really enjoyed SMTM's "A Chemical Hunger" series[1]. But recently they've gone into weird fad-diet territory with their potato obsession.

Like, they crow that the potato mono-diet "works," in that the people who successfully followed it lost weight. Well, sure -- all of those 70s fad diets "worked" in that sense! Grapefruit and popcorn? Sure, you can lose weight on that!

But their own numbers show that people regain the weight after they start eating other foods again: "On average, people gained back most of the weight they lost."[2]

People who successfully follow very restrictive diets will lose weight... as long as they follow it. And these "riffs" in the OP where it's potatoes and bacon, or potatoes and gummi worms, or whatever, won't change that basic observation.

[1]: http://achemicalhunger.com/

[2]: https://slimemoldtimemold.com/2023/01/26/smtm-potato-diet-co...

[n2d4]

I found A Chemical Hunger interesting when I first read it, but later people pointed out a whole bunch of severe mistakes (eg. [1] [2] [3]).

I don't know, I'm not a nutritionist, but the inaccuracies plus all the potato-conspiracy stuff made me doubtful of SMTM. My main takeaway was that no one, not even people in the field, really knows how food works.

[1] https://nothinginthewater.substack.com/p/contra-smtm-on-obes...

[2] https://basedprof.substack.com/p/smtm-mysteries

[3] https://someflow.substack.com/p/criticisms-of-a-chemical-hun...

[DominikPeters]

There are also these posts, pointing out many inaccuracies:

https://www.lesswrong.com/posts/NRrbJJWnaSorrqvtZ/on-not-get... https://www.lesswrong.com/posts/7iAABhWpcGeP5e6SB/it-s-proba...

SMTM have never responded to it, and they have lost my confidence for that reason.

[Aurornis]

> I really enjoyed SMTM's "A Chemical Hunger" series[1]. But recently they've gone into weird fad-diet territory with their potato obsession.

I wanted to enjoy that series because exploring alternate factors in obesity is interesting, but the series similarly went into a weird obsession with lithium as an explanation for everything. He almost immediately started ignoring evidence that didn’t fit his theory and obsessively focused on cherry-picked evidence that was favorable to the story he wanted to tell.

Others have posted links to various debunking articles of the series, but the part that made me lose interest was even earlier: He has a section where he acknowledged that caloric intake was up over the same period of increased body weight, but then tried to dismiss this as irrelevant. I can’t take anyone’s writings on obesity seriously if they don’t believe increased caloric intake is correlated with increased obesity.

The series is written in a rationalist style that appeals to many people, but the content and logic within were not very scientific or even representative of the sources he cited at times. It’s a good example of how the right prose can be very convincing.

[lm28469]

> But their own numbers show that people regain the weight after they start eating other foods again: "On average, people gained back most of the weight they lost."[2]

Every single diet suffers from that, because you don't need a diet, you need a life style and as the name implies it, it has to be sustained for your whole life

[Aurornis]

The difference is that fad diets are unsustainable from the start. Technically someone could try to continue a diet like this indefinitely if it had sufficient nutrients, but most people will get sick of a fad diet after a while and revert to their prior eating habits.

The difference between a fad diet and a good diet is that a good diet is designed to be sustainable from the start. The goal of a good diet is to reset your eating habits into a healthier set of foods that you can still enjoy and continue eating regularly indefinitely.

[zoklet-enjoyer]

A potato lifestyle

[jwestbury]

It's important to recognise that even with "lifestyle" changes, weight loss is often not sustainable. Here's a quote from a review of the literature undertaken in 2018[0]:

> In a meta-analysis of 29 long-term weight loss studies, more than half of the lost weight was regained within two years, and by five years more than 80% of lost weight was regained

Or, to offer some anecdata, I lost 60 pounds in early 2012. I started working out. In 2015, I hiked every weekend, totaling more than 400 miles of distance covered, and more than 20 miles of elevation gain. And in 2016, while training for a trek in Peru, I injured myself and was unable to exercise for quite a while. I gained about 20 pounds back, but then stabilised -- until COVID, when high stress and a forced change in dietary habits (I couldn't go to the grocery store easily, and many foods were routinely out of stock) means I ultimately gained back the remainder of my weight, some eight and a half years after losing it. In particularly extreme examples,

Generally speaking, weight loss as a goal is destined to fail. Even when significant habitual changes are effected, the reality is that people's metabolism is hugely impacted by their early life. Furthermore, weight loss has often been found to increase levels of hunger[1], which makes it incredibly difficult to sustain. And in extreme cases -- such as the Minnesota Starvation Experiment[2] -- low-calorie diets (in this case, actually about 1600 calories a day) can cause persistent decreases in both basal metabolic rate and satiety, which means those who have lost weight will not only find it harder to maintain the weight due to a decreased caloric requirement, but also because of increased hunger.

The tl;dr here is that sustained weight loss may be possible, but the best bet is probably weight loss which occurs over a period of a decade or more, because any faster and you start to risk some paradoxical outcomes which will make it increasingly difficult to maintain.

0. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5764193/ 1. https://www.nih.gov/news-events/news-releases/weight-loss-le... 2. https://en.wikipedia.org/wiki/Minnesota_Starvation_Experimen...

[WorldMaker]

> But their own numbers show

This is part that keeps this potato diet stuff interesting to me is that they've been extremely open with the numbers, from the very beginning. Most fad diets you have no idea how many people participated or the particulars of their habits during the participation period and there was no follow-up at all beyond the participation period.

I don't think SMTM has "cracked" anything with the potato diet yet and I don't expect to see useful "answers" from SMTM, but they've been good so far at some of the raw bits of science: finding ways to ask interesting questions and recording as much data as possible about it, publishing that data, and then finding interesting new questions from that.

Sometimes I feel rather cynical that we'll not see any answers in my lifetime, but I appreciate a blog asking interesting questions and then trying to data science what they can around them to find more useful questions.

[axiomaticdoubts]

I think it's worth pointing out that they've also said multiple false things in their blog posts, and have refused to address or fix them despite repeated requests over a period of more than one year. I think people should be careful before believing in things they read in SMTM's blog. See e.g. https://manifold.markets/Natalia/how-many-of-these-falsemisl...

[yungporko]

i don't understand what you're trying to say here, of course anybody who loses weight by changing their diet will gain the weight back if they go back to eating the way they were before, isn't that just common sense?

[Taikonerd]

Well, I guess I'm saying a "good" diet is one that can be sustained indefinitely. The fact that an extreme diet produces good results in the short term isn't surprising or interesting, because virtually nobody can (or should) follow an extreme diet for the rest of their life.

[tech-historian]

A diet that you can follow forever is called a lifestyle. For many diets and many people, it's really hard to convert into a lifestyle, because the of the restrictions and predictable cravings.

Side note, there's a thing called the Potato Hack [0] that proposes 3-5 day potato-only diets for short term fixes. A "potato fast" if you will.

[0] https://potatohack.com/

[bee_rider]

A lifestyle involves all sorts of non-diet things.

It is a bit odd, though, that we use “going on a diet” to describe a short term change.

But I think the most accurate phrase would be that you’ve “changed your diet,” (implicitly, permanently).

[kbelder]

Sometimes, though, an extreme diet to lose weight can allow you to make some lifestyle changes (such as exercising regularly) that do have lasting impacts. Being significantly overweight can really make physical activity difficult and demoralizing.

I agree that it they often aren't sustainable and need to transition into a more sensible long-term diet.

[lawlessone]

We really need multiple words for diet.

It means at least two different things:

It can refer to specific planned period of eating a certain way to achieve a certain end.

e.g. Atkins diet(please look up how he died before considering this), fodmap diet , low GI diet, potato diet

It can also refer to the normal way a particular person at particular place and time in history eats.

e.g The Roman diet, Celtic diet, American Diet, French diet, Pandas diet, Neanderthal diet ,Vegan/Vegetarian diets, Kosher/Halal diets

[dminor]

Atkins died of a head injury when he slipped on some ice, FYI

[bscphil]

He also had congestive heart failure and his arteries were 30-40% blocked a year before his death. After he fell, he died during surgery to remove a blood clot in his brain. It's hard to say conclusively what caused his fall and ultimately his death, but we do know for a fact that he had heart problems.

I don't believe this matters either way, though. You shouldn't be basing your understanding of what a healthy diet looks like on the outcome for one individual. Experts in the field of human health do not believe that Atkins' diet was healthy, and that should suffice (though of course there are plenty of other unhealthy diets, some of which have problems that Atkins avoids).

[isk517]

I would imagine extreme diets are for viable for those that require extreme weight lose. Someone looking to lose 100+lbs would be able to use it to lose enough weight to become active again and start to make lifestyle changes that will support long term weight management. People looking to drop 10lbs though are very likely to gain it back once they start eating like a normal human again.

[ajmurmann]

I don't think SMTM is proposing the potato diet as a permanent weight loss dilution, but think that there is something weird going on here that might result in a permanent dietary recommendation if understood. For example, we might find that the potassium is causing the weight loss and supplementing high doses of potassium could be something you do permanently.

[axiomaticdoubts]

There've been multiple studies that gave people potassium supplements and measured their body weight. (Primarily because potassium helps lower blood pressure). They haven't found that potassium causes weight loss. See my meta-analysis here: https://docs.google.com/document/d/1sR1T2Kb1X1fCLYeEE-U3Rwei...

[ajmurmann]

That was just an example. They are doing this weird riff model because right now there are too many variables

[bensecure]

He's saying that this is a well established fact regarding every fad diet. Usually in the sciences, a new method measures itself against a "control", which might be a placebo or non-treatment, but might be another well established treatment, such as a drug for the same disease. For a fad diet, a sensible "control", or "null hypothesis" would be another fad diet, not involving potatoes. One would only have grounds to say that this fad diet worked if it worked better than the best alternative fad diet.

[nightski]

I'd argue it's a well established fact of any diet, regardless of how it is lost. Changing your body's natural weight long term is very difficult no matter what you eat.

[candiddevmike]

You'd think there would be some long term benefit to fad diets around the lines of hunger suppression or helping folks better recognize when they're "full".

IMO, there's a psychosomatic angle for restrictive diets that is similar to a placebo.

[Taikonerd]

At least for the 70s fad diets, there wasn't any sort of long-term benefit like that. When they stopped, people would return to their original weight, or maybe even a little more. Then they would freak out and go back to the diet again -- the infamous "yo-yo dieting."

But I do think it's true that there are two different sensations: hunger, versus wanting food because it's yummy. Maybe some future diet will pair a restrictive diet with some sort of guided meditation helping you discern the different signals your stomach can send you.

Or maybe Mounjaro and friends will make the whole point moot ;-)

[matthewdgreen]

Do you think Wegovy/Ozempic/Mounjaro also work due to placebo effect? It seems that over the past decade or two we’ve discovered (some elements of) the sophisticated physiological mechanism by which we regulate appetite, and it involves the production of various hormones within our lower intestinal tract. When some fad diet produces sharp appetite reduction, my general question is: what’s more reasonable? To assume placebo or disruption of this mechanism?

At very least I think it’s useful to reinterpret these extreme fad diet weight loss results in light of this knowledge, rather than defaulting to the (now obsolete) understanding that appetite is primarily determined by psychological effects.

[axiomaticdoubts]

"A Chemical Hunger" has multiple inaccuracies that have never been addressed or corrected. For example, they made up the "fact" that wild animals have been getting fatter out of thin air. See https://www.lesswrong.com/posts/NRrbJJWnaSorrqvtZ/on-not-get...

[alecst]

The way I see it, the point of the very article you're replying to is to find a friendlier version of the potato diet that might be more fun or sustainable.

Maybe they'll find that people who replace one of their daily meals with french fries end up losing weight over time. Who knows. I think it's good to be positive.

[Taikonerd]

Oh, totally -- I was interested in their "half-tato" idea, because it seemed more sustainable than the all-potato version. But the results were "underwhelming," in their own words. Ditto their potassium-salt idea.

[merpnderp]

Once you find a diet that is healthy and works, I don't think you're supposed to ever get off of it. It's kind of a tautology that the people getting off their diets gained back their original weight.