If you’ve read the excellent series A Chemical Hunger by Slime Mold Time Mold, you’ll have come across a post describing 8 Mysteries about Obesity that most common models can’t seem to explain.
These mysteries were what originally got me started thinking about obesity and experimenting. Sure, I was obese myself (probably near 300lbs at the time I read it), so it was also personal. But while I might’ve had some of the facts regarding these mysteries floating around in the back of my head, they definitely weren’t on full display, and especially not connected to each other.
Presented together, and so dramatically, made me realize my own model of obesity was clearly wrong. I remember the one that hit me the hardest: this map of obesity by counties in the U.S.
Ok, sorry. But if your theory of obesity can’t explain how I can see the Rockies and the Sierras and the Mississippi delta and the Appalachians on this map, then you better go back to the drawing board.
Is the food in Louisiana more delicious than the food in Colorado? Do people not count calories in Maine, but they do in Vermont?
But I get ahead of myself.
This post is my own attempt to reconcile my current Mental Model of Obesity (tm) with those mysteries. If you haven’t, I recommend you read at least the article about the mysteries from that SM TM series. This will make much more sense if you’re at least somewhat familiar.
My current mental model is mostly stolen from other people who’ve been thinking about this for much longer than I have. That is to say, I didn’t come up with any of the parts. I’m just trying to integrate them into my own understanding.
Summary of Seed Oil Theory
Obesity (and many other conditions/diseases) is caused by long-term dysfunction of mitochondrial energy metabolism.
The breaking changes were probably largely changes in our food intake that started in the late 1800s and accelerated in the 1930s and 1970s.
Just going back to the previous ways won’t necessarily fix a broken metabolism, just like driving at low RPMs won’t unseize a cylinder in an engine (ask me how I know).
Individuals have individual responses to these changes, with some almost immune, while others are extremely susceptible.
In most people, the damage is cumulative, which is why we (now) gain more fat as we get older. This is why some people can get away with stuff for some time, but almost nobody can get away with it forever.
It’s probably seed oils. More specifically, linoleic acid.
There is a somewhat complex causality graph at play here. If a kid kicks a ball into the street, causing a car to swerve into a mailbox, did the kid cause the crash, the ball, the driver, or the postal service? Yes.
This is referred to by some as “hammer and nail theory” and I frankly don’t have a better name.
In practice, this means that there are things (nails) that, once you have metabolic damage (hammer), you can no longer eat without suffering negative consequences (e.g. carbs, sugar, too much protein, too many BCAAs, carbs mixed with fat) even though a metabolically healthy person can handle them just fine.
This is why doing what a healthy person does is usually not helpful. Since the causal factors are everywhere in modern society, a healthy person is by definition an outlier in their resistance/immunity to them. Without the hammer, the nails are not a problem.
It’s also why many arguments from anecdotes or epidemiology aren’t particularly useful, e.g. “See, I can mix carbs & fat and I have abs!” or “The X people have eaten 80% calories from rice for thousands of years, and they are/were thin and healthy!” Yes, a bunch of nails are harmless if nobody is running amok with a hammer. Yes, you can drive around in the rev limiter for a long time if your engine is well-oiled and the coolant system works.
What’s the best way to un-hammer yourself? Unfortunately, I don’t think we know precisely. But it probably involves resaturating your body fat and tissues. My own ex150 is one attempt, a hyper-low-carb, hyper-low-protein, extremely-high-dairy-fat diet. Brad from Fire in a Bottle is trying a low-fat, high-cornflakes diet combined with supplements. Some people seem to have success with the Potato Diet.
By the way, SM TM themselves investigated the seed oil theory of obesity, and they came away unconvinced.
So how does this theory deal with the Mysteries?
Mystery 1: The Obesity Epidemic
Why did obesity go from ~1% in 1890 to ~40% today?
In short, seed oils.
Polyunsaturated fats go from a little over 10g/day/person to nearly 40g since 1900.
Monounsaturated from 50g to 70g.
Saturated fat stayed the same.
This post by Tucker Goodrich is excellent on the history of seed oils.
Verdict: seed oil theory checks out.
Mystery 2: An Abrupt Shift
Why is there seemingly a drastic jump in obesity since the mid-1970s?
I’ve seen some people trying to argue this “jump” away. If you take an exponential-ish curve, it will always look like there’s an inflection point somewhere.
If the graph above is correct, the obesity rate of men was 10% in 1960, and that of women was about 15%. That means the rates already went up 10-15x since the 1% from 1890. Going from that to today’s rates is only a quadrupling.
Then again, there’s a graph included in SM TM’s own post about seed oils that seems to correlate quite well:
The jump might be a statistical artifact, or maybe this Jeff Nobbs character got it right, and seed oils really started going up and to the right in the 1970s.
Also, in the 1970s, canola oil was invented:
Rapeseed oil has long been used in industry as a lubricant for engines and other machine parts, but, because of its high level of potentially harmful erucic acid, it was not considered safe for human consumption (though it was sometimes added to animal feed).
It was not until the 1970s, when Canadian scientists developed a hybrid that contained a very low level of erucic acid, that experimentation began to place rapeseed oil among the vegetable oils available for use in cooking.
Verdict: seems to check out, if the jump is indeed real.
Mystery 3: The Ongoing Crisis
Even since 2010, obesity has increased massively.
Whoops, looks like seed oil (mostly soybean oil) consumption increased by 50% (!) since 2010.
Verdict: check check check.
Mystery 4: Hunter-Gatherers
Why are modern hunter-gatherers lean?
This is going to sound weird, but hear me out: it’s seed oils.
Modern seed oils were only introduced in the 1800s, after the industrial revolution. Some extraction mechanisms are much more recent. For example, the production process of soybean and canola oil involves the chemical solvent hexane and industrial-scale chemical or propeller extraction machines.
And as we saw in the Britannica article above, canola oil was only invented in the 1970s. Fat chance that hunter-gatherers are hybridizing plants and using hexane to extract oil from them. How many chemical engineers does the average hunter-gatherer tribe employ?
Verdict: checkity check.
Mystery 5: Lab Animals and Wild Animals
Why are lab animals, rodents, and maybe even wild animals getting more obese?
There’s apparently some controversy if wild animals are indeed getting more obese, and how wild a real wild animal has to be to be a wild animal. But it seems less controversial that animals around humans are getting fatter. Guess who’s feeding them?
What’s interesting is that, if you read enough nutrition studies, you will notice the ubiquitous “obesogenic high-fat diet.” When researchers want to fatten up lab rats or mice, they give them a high-fat diet. One of the most common ones is 60% calories from fat (Stephan Guyenet on this).
What fats are in the high-fat diet, you ask?
The most commonly used diet is Research Diets D12492, which is 60% fat by calories, and composed mostly of lard, soybean oil, casein, maltodextrin, sucrose and cellulose.
Oh, lard? According to this Fire in a Bottle article, lard is often up to 19% PUFA:
The high saturated fat being referenced is lard and they
analyze the lard they are using: 35% saturated, 36% MUFA and 18.8% PUFA!
Turns out that pigs are monogastric, like us. When you feed them soybean oil (as is usually the case in at least U.S. pig feed), they store that in their adipose tissue. So the seed oils are leaking through the meat supply. Beef is better because cows have multiple stomachs and can convert nearly everything to saturated fat. A study compares grass-fed vs. grain-fed beef.
Chris Masterjohn followed up on this Research Diet:
I got an email today from Dr. Matthew Ricci, the Vice-President and Research Director of Research Diets, the company that produces the infamous 60% fat, lard-based rodent diet D12492. I've written about this diet before. The company had previously been using the USDA database to determine the diet's fatty acid profile, but recently had it directly analyzed, knowing that the fatty acid profile of lard can vary according to what the pigs are fed.
It turns out that the diet obtains 32% of its fat from PUFA instead of the previously reported 17%. The ratio of omega-6 linoleic acid to omega-3 linolenic acid had been previously reported as 7.8 but is actually 14.
Oh, now we’re up to 32% PUFA content, great.
It’s actually comical when you read a lot of these papers. The common “saturated fats” are never, you know, coconut oil, or cocoa butter, or butter, or beef suet. It’s always PUFA-laden lard or palm oil. (Not the more saturated palm kernel oil.)
So at 60% of fat from calories in the diet, 32% of the lard fat from PUFA, and soybean oil in there as well, these lab animals are getting at least 20% of their calories from PUFAs. No wonder that they’re getting obese. Also: casein is probably just about the worst protein you could use for this, too, as it seems very inflammatory. Many people who are allergic to dairy are specifically allergic to casein, and maybe this is true in mice as well.
But don’t forget, it’s those darn high-fat diets! Nothing to see here, folks!
Verdict: checkmate.
Mystery 6: Palatable Human Food
Why do lab rats get obese more quickly on a human-like “cafeteria diet” than on the aforementioned high-fat diet?
Probably: hammer & nail.
The effect of seed oils as proposed by the likes of Hyperlipid, Fire in a Bottle, Chris Masterjohn, Jeff Nobbs, and Tucker Goodrich isn’t that seed oil intake linearly makes you more obese because the PUFA-calories are somehow evil.
It’s a very specific mechanism, in which linoleic acid in even relatively small amounts (typically estimated at ~7%+ of calories) begins disrupting the satiety-signaling function of cell mitochondria.
Thus, linoleic acid is the hammer, and carbs (or anything else, really) are the nail. Once your satiety signal is destroyed, sugar makes many people (and presumably rats) insatiable. Interestingly, the same is true for a smaller percentage of people with protein. I count myself among them: I can eat protein until I’m bloated, and I’ll be hungry again 30 minutes later.
By the way, I find the way scientists talk about the “cafeteria diet” to be mystical to the point of being comical. Really, you couldn’t recreate lab chow that made the rats as obese as the human cafeteria diet? Weird, the cafeteria managed to do it.
They somehow imbue “human junk food” with a mystical, obesogenic property that cannot be explained by the sum of its parts, almost like the immortal soul. Please. You could start by differentiating fatty acids.
Verdict: could check out, but less obvious.
Mystery 7: Altitude
Why does obesity correlate negatively with altitude?
Ah, full circle. Back to my favorite map:
I don’t believe people in the Mississippi delta eat more seed oils than those in Colorado. I mean, maybe a little. Coloradions eat healthy and stuff. But to this degree? Doubtful.
My theory: something about the high altitude is just mitigating the damage. But Colorado’s overall obesity rate still went up, telling us Coloradistas are not immune to the effect, they’re just lagging behind.
What exactly is it? The most plausible idea I’ve heard is that lower oxygen increases mitochondrial function. If mitochondrial dysfunction is really at the root of obesity, this would help explain it.
Verdict: I could see it, but not exactly a slam dunk.
Mystery 8: Diets Don’t Work
Why don’t diets work?
Because they don’t ruthlessly exclude seed oils. Those that do seem to work much better. See the potato diet, my own 50lbs weight loss over 6 months, or the recent ex150 trials where people lost 11lbs, 8lbs, 15lbs, and 9lbs over 30 days (and spoiler alert, there’s another 13lbs case study I’m currently writing up).
Seed oils are the background radiation of modern food
The nasty thing, if seed oil theory is true: even the tiniest amounts ruin you. Some PUFAists consider 2% of calories from PUFA to be the “natural” level. That means that out of my ~3,500kcal TDEE, I can have 7.7g PUFA. As a reminder, that’s less than 2 teaspoons per day.
I thought I was avoiding seed oils for years, after all I wasn’t cooking with them, right? But they’re in almost literally everything.
Go to the store with a friend and play seed oil-roulette one day. Just take turns picking up random items and checking the ingredients.
Bread? Soybean oil.
Cupcakes? Canola and soybean oil.
Salad dressing? Sunflower oil.
Cake? Soybean oil.
The unfortunate truth is, you probably have to cut out nearly all restaurant foods, nearly all processed foods, and even harmless-seeming “health foods.”
On keto, I’d order the salad at most places. Turns out almost all commercial salad dressing is majority soybean or canola oil.
You can’t even eat commercial chicken or pork in serious quantities, because they’re fed soybean oil and soybean meal and they store that in their own body fat. So you’re eating it, too. As we saw earlier, 18-32% of pork fat is PUFAs.
Unhammering your metabolism
One other nasty effect if this theory is true: if you’ve gotten fat eating seed oils, you have presumably stored those PUFAs in your own adipose tissue (assuming you’re monogastric like a pig, not a cow). When you subsequently burn your own body fat, you’re burning said PUFAs in your mitochondria, where it begins messing you up again.
This might be why almost all diets are self-limiting. After a certain amount of fat loss your metabolism turns down, you become hungry all the time, and eventually willpower is not enough to keep going.
What could possible solutions be?
Spamming SFA intake to balance PUFAs
I suspect that I accidentally found a (partial?) solution with ex150: besides avoiding seed oils pretty much completely, it also has an answer to this rebound-effect.
Since ex150 is extremely high in saturated fat, that might balance the ratio at which fatty acids are oxidized in your mitochondria. I’m flooding the system with so much saturated fat that, no matter how much PUFA is released from my body fat, the ratio is at least decent.
Burning fat in the flame of carbohydrate
Brad from Fire in a Bottle just posted a video about Cornflakes for weight loss, and it’s pretty much what it sounds like. He is supplementing with stearoylethanolamide, which he is hoping will circumvent the negative effects of burning your own, stored PUFAs. He only just started the experiment, but it sounds promising.
Also ran…?
Are there other solutions? Possibly. A lot of people are looking into this and I’m excited to learn what they find. Maybe it’s a certain diet. Or getting more sunshine. Or a certain supplement. Or ice baths. Who knows, it might be what color socks you wear for all I know.
Verdict: better than any other explanation I’ve seen.
Conclusion: it’s definitely seed oils
While the 8 Mysteries of Obesity started out confusing and astonishing me, seed oil theory explains them better than anything else I’ve seen.
A few of the points aren’t 100% slam dunks, but I think most are spot on:
The Obesity Epidemic - spot on
An Abrupt Shift - spot on
The Ongoing Crisis - spot on
Hunter-Gatherers - spot on
Lab Animals and Wild Animals - spot on (for lab animals)
Palatable Human Food - not a total slam dunk, but better than “cafeterias”
Altitude - not a total slam dunk, but good explanation
Diets Don’t Work - only workable theory I’ve ever seen, explains crazy outliers
That’s where my current thinking is at. If you’re intrigued or skeptical, I encourage you to spend way too much time reading the following, who have all done great work on seed oils:
Jeff Nobbs (and Zero Acre Farms)
Hyperlipid (I won’t pretend to understand much here, super technical)
Edit:
And, of course, somebody has beaten me to this by nearly 2 years. Check out A Response to A Contamination Theory of the Obesity Epidemic.
Edit 2:
Slime Mold Time Mold have posted a reply to this post, titled Still not Sold on Seed Oils.
I'm going to raise you on this. It's not just the obesity epidemic, it's the whole 'epidemic of hypothyroidism that doesn't show up on thyroid tests' that's been going on since about 1970 (which is when they changed from diagnosis by symptoms to diagnosis by TSH test)
I think these wretched polyunsaturated things gum up your metabolism somehow, and lower your body temperature and run you out of energy for all your systems. If part of that is that they break satiety signals at the same time that gives you obesity, going along with CFS, fibromyalgia, depression, IBS, and all the other stuff that looks just like hypothyroidism.
https://www.lesswrong.com/posts/4FqHN9cWWcjC9qMMo/a-response-to-a-contamination-theory-of-the-obesity-epidemic
lol beat you to it