Saturated fats, polyunsaturated fats, and carbohydrates

Discussion, in general

Saturated fats, polyunsaturated fats, and carbohydrates

Postby cmsellers » Mon Nov 26, 2018 1:59 am

So I recently read a book called The Big Fat Surprise, and I feel what's contained therein (and in some similar books I also hope to read) merits a thread. But first I feel I should cover a brief history of my thinking in dietary matters; I'll put it in spoilers if you want to skip over this part.

What I used to believe
As kid, I was taught that fats of all kinds, but especially saturated fats were public enemy #1, followed closely by salt and sugar. I was taught that we needed a tablespoon of fat to function, but should try to get it from non-animal sources and try to stay as close to the one tablespoon a day of fat as possible. Similarly, we needed a teaspoon of salt a day and should try not to go above that. Sugar should be used sparingly, but was not as bad as fat or salt, and any carbohydrates that were not refined sugar were good. Whole grain foods were preferable to refined grains, but only because they were a source of fiber—I was never taught that refined starch was inherently harmful.

Since that time, the Mediterranean Diet overturned our understanding of fats, and it became clear that monounsaturated fats were good for you and it seemed like polyunsaturated fats were as well. Then it came out how awful trans fats were, and learning that we'd known about this for decades but everyone had somehow ignored the evidence was truly appalling. I read Michael Pollen and decided that the best diet was one based as much as possible on whole plant-based food with occasional meat or dairy, and though I could never get my consumption of meat and dairy down all that much, I did make sure that I was mostly consuming skim milk, fish, and turkey.

I decided that the US was wrong on salt, at least for me personally, when my mother, who had long limited salt, was diagnosed with low blood pressure and ordered to take a teaspoon mixed in water every night. As a result, I started using as much salt as I wanted, which comes out to probably a little under a tablespoon a day. When I actually got serious about losing weight, I realized that the USDA was still recommending a ridiculously low-fat diet, and saying that at least three servings a day of refined starches constitutes acceptable eating, and I decided that the USDA was not a reliable source on nutrition, so I started trying to find other sources of nutritional information, which eventually led me to this book.

Going into the book, I believed that fiber and protein are macronutrients that should be maximized as much as possible, while refined sugar, saturated fat, and refined starch (in that order of badness), should be restricted as much as possible. Monounsaturated fat is good for you but should be somewhat restricted because it it calorie-dense, while polyunsaturated fat, especially if it contains omega 3's, is probably good for you but should be similarly restricted. The sugar in fruits is good for you because it's bound up in fiber, but should be eaten in moderation to prevent insulin spikes. Unrefined starch probably varied, with the starch in brown rice behaving in similar fashion to sugar and the starch in green banana flour behaving similar to soluble fiber, but since I didn't know how to tell what was what, starch in unrefined high fiber whole grains should be fine in moderation.

At meals I was trying to achieve a balance of starch and fats (ideally monounsaturated as much as possible), which would taste good, maximize the fiber and protein I consumed, and leave me feeling full. I believed that the book was going to demonstrate that the acceptable quantities of saturated fat are probably higher than we acknowledge, but that the precautionary principle would suggest that I still limit them as much as I could without taste.

What the book is, it turns out, is a history of the evolution of our understanding of dietary fats, complete with detailed descriptions of each study which drove the scientific consensus we've seen since 1961. And something becomes clear: the scientific consensus that fat is bad is as recent and well-supported as the legal consensus that the Second Amendment protects an individual right to bear arms, and came about in pretty much the same way.

In the fifties, a charismatic man named Ancel Keys believed that dietary cholesterol, which he later switched to dietary fat and then saturated fat, caused both obesity and heart disease. He conducted a bunch of studies trying to prove this, which never actually supported his hypothesis, but he managed to Wayne LaPierre the American Heart Association, which was the major non-governmental source of funding for heart disease research. From his position at the AHA, he managed to win over other people with the money he controlled and the force of his personality, and eventually the US government, the other major source of funding for dietary research. Once that happened, studies intended to prove saturated fat was bad got funded, studies which intended to prove saturated fat was not bad didn't, and studies which accidentally proved that saturated fat was not bad got spun into suggesting it was anyways or swept under the rug.

The evidence for the idea that saturated fat was bad basically rested on three planks: First, Keys had conducted a massive epidemiological study, in which he selected countries which he expected to have low rates of fat consumption and low rates of heart disease, or high rates of fat consumption and high rates of heart disease, ignoring all the countries which evidence at the time had suggested would disconfirm his model. Despite this, he still had to engage in shitton of academically unethical behavior to get the results he wanted.

Secondly, he reasoned that it was common sense that because fat has twice the calories per unit of weight as carbohydrates and protein, people eating fat will feel less sated: fat makes you fat. Though older studies had already demonstrated that hunger is connected to insulin and fat is the only macronutrient that doesn't spike insulin, he and his followers ignored this for a conclusion that was so common sense they didn't even feel the need to test it.

Finally, studies of saturated fat consumption have fairly consistently shown that it increases cholesterol, and later showed that it increases low-density lipoproteins, a measure of the bad cholesterol, and there is also a correlation between LDL cholesterol and heart disease. Almost universally, these studies showed that diets high in polyunsaturated fats and/or carbohydrates were worse on all other health indicators measured, including resulting in low high-density cholesterol, a better marker for heart disease than high low-density cholesterol. Furthermore, epidemiological studies consistently showed that diets high in polyunsaturated fats and carbohydrates have higher rates of mortality from heart diseases, higher rates of mortality from cancer, and higher mortality overall. More recently, it was discovered that it is only a certain kind of low-density lipoprotein associated with heart disease, which stearic acid raises not at all and other saturated fats only marginally.

However the medical establishment has continued to push the "saturated fats are literally poison" narrative, despite the evidence that polyunsaturated fats and carbohydrates are worse and the fact that the entire basis of the assumption that saturated fats are bad for us has collapsed underneath them. From the wreckage of their discredited hypothesis, they soldier on, admitting that refined sugars and starch are bad for you after all, but insisting that saturated fat is still at least as bad. Based on what the author describes, the reaction of nearly every one involved in the diet science community in the US (except the handful of dissenters) has been to shrug and say that they haven't read the original studies themselves, but the science is well-established, Richard Atkins was a charlatan, and Gary Taubes is a crackpot. When they engage with dissenters at all, they engage in appeal to authority and ad hominem and the occasional red herring because their position is literally indefensible.

I think that there are several reasons that the diet science community has been so stubborn. The first is of course institutional inertia. From Richard Owen to Noam Chomsky, I've seen in plenty of other fields how one charismatic and well-respected figure can set an agenda which teaches the next generation of researchers that bad science is settled science, sending them down the wrong path. Then the people whose reputations were built on these assumptions cannot admit to being wrong.

The second is puritanism: particularly in America we tend to believe that anything enjoyable should by definition be bad for you. The third is corporate funding and lobbying. Who do you think has more clout: the big bad meat and dairy industries or the combined influence of the wheat, corn, soybean, vegetable oil, and manufactured food lobbies? The efforts of soy and vegetable oil producers in particular to vilify saturated fat and suppress research on trans fats is a disturbing trend throughout.

And the final issue, I think, is that a lot of people, especially the kinds of people who get into diet science, see compelling moral reasons to be vegetarian or vegan, whether for environmental, animal welfare, and/or animal rights reasons. They're not entirely wrong on the first two points, but one of my pet peeves is the way that vegans consistently lie about the health effects of a vegan diet, and this seems like a much more nefarious version of that. If the evidence suggests that we should probably be eating more saturated fat and protein, not less, then we need to start by acknowledging that reality and then we can have a discussion about how to do this in a manner which is humane, sustainable, and affordable for the great mass of humanity. Tricking humans into eating an unhealthy diet because misrepresenting the science will prevent the misery of animals is, to my mind, frankly evil.

So I've read this book, and I'm excited, in the sense that I am experiencing a mixture of strong emotions. I am relieved to realize that the evidence suggests that there is no reason to cut back on saturated fats, and indeed I should probably be eating more of them. I am anxious, because I'm not entirely sure where to go from here. The actual evidence suggests that a ketogenic diet is the best way for obese people to lose weight and improve their overall health. It's also the way that the only three people I know of who have achieved sustained weight loss initially lost weight. However I've stocked up a lot of whole grains, and eating a low-carb diet is expensive, and given that I don't like green vegetables, I'm worried about getting sufficient micronutrients if I cut fruit out of my diet. Do I keep doing what I'm doing (only with more saturated fats), which seems to be yielding small but steady results, or do I make the switch to a ketogenic diet in the hope of drastically improved results?

Warning: long rant
But the main emotion I'm feeling is extreme anger. Anger that this diet was pushed on the entire population, including children, in the face of so little evidence, as a massive experiment without controls or informed consent. Anger that the medical establishment continues to mostly ignore the evidence, and in fact has doubled down on the benefits of high-carb, low fat diets. Anger at the realization that the extremely low-fat diet my mother inflicted on me as a kid and teenager may explain a lot of both health and mental health issues.

I feel anger at the massive, longstanding, and ongoing perversion of the scientific method to support an ego and an agenda. I've seen massive fuckups in the scientific consensus before, and I've seen fuckups in the scientific consensus that have lasted for generations, but none that were this big and this long lasting, none that had supporters who were this obstinate in the face of overwhelming evidence, and certainly not that had such serious implications for so many people.

And I'm angry at the thought of the vindication this will give the global warming deniers and antivaxxers if they ever figure this out. It doesn't matter that the science of vaccines and global warming is far better than the science on saturated fats: the repeated and continuing massive fuckups by the government and the entire field of diet science will give aid and comfort to science deniers for generations if the government and diet science community ever fess up to their error, as I believe they are absolutely obligated to. For that matter, how can I trust the scientific consensus in any field myself unless I go and read all the original papers, something ain't no one got the time for, or someone else goes and writes a similarly detailed book or meta study?

I'm furious, and I'm going to read some of the other work on this subject, but in the mean time, I cannot recommend this book to all y'all highly enough.
  • 6

User avatar
cmsellers
Back-End Admin
Back-End Admin
 
Posts: 9316
Joined: Sun Apr 14, 2013 7:20 pm
Location: Not *that* Bay Area
Show rep
Title: Broken Record Player

Re: Saturated fats, polyunsaturated fats, and carbohydrates

Postby Kivutar » Tue Nov 27, 2018 5:17 am

Unpopular opinion: we really don't need to eat starch. Yeah, zero starch isn't good, but it should be more "a handful of rice in the stew" than "side dish," let alone the major source of calories. I exclude root veggies from this because they're full of vitamins, but we'd be better off if we didn't eat rice, bread, porridge, etc.

I was never obese, but I've certainly lost a lot of flab by cutting out most starch. There's definitely been no downside either.
  • 6

Then the LORD said to me, "Go again, love a woman who is loved by her husband, yet an adulteress, even as the LORD loves the sons of Israel, though they turn to other gods and love raisin cakes."

Hosea 3:1
User avatar
Kivutar
Champion
Champion
 
Posts: 1425
Joined: Wed Apr 01, 2015 3:52 am
Location: Right behind you
Show rep
Title: Great Librarian

Re: Saturated fats, polyunsaturated fats, and carbohydrates

Postby Anglerphobe » Tue Nov 27, 2018 7:59 pm

I did find some loss of energy and apparent loss of strength from cutting carbs. I ended up increasing it back again incrementally until I felt my best, which turned out to be somewhat more than proportion you are typically advised to cut to.
  • 3

"Tusser, they tell me, when thou wert alive,
Thou, teaching thrift, thyselfe couldst never thrive.
So, like the whetstone, many men are wont
To sharpen others, when themselves are blunt."

Anyone who has any kind of opinion fucking disgusts me.
User avatar
Anglerphobe
TCS Junkie
TCS Junkie
 
Posts: 2160
Joined: Fri Mar 06, 2015 6:03 pm
Show rep
Title: round Earth shill

Re: Saturated fats, polyunsaturated fats, and carbohydrates

Postby Piter Lauchy » Wed Nov 28, 2018 6:55 pm

Calling fat fat is just bad marketing. Let's start a petition to call it slim instead.

In all seriousness though, I'm a disgustingly lazy person and slathering some shit onto a slice of bread is just that much easier than preparing healthier food. I'd like to be healthy all around, but it's just so darn inconvenient.
  • 4

The Oatmeal wrote:Live life passionately and love everyone like they are family, because Jesus is always with you. Jesus loves you seriously bigtime. He'd hug you until your eyeballs exploded out of your skull if he ever met you. He'd windsurf across oceans of dead Nazis which he personally slaughtered just to tell you that your new haircut is the bee's knees. [...]
Praise Jesus, especially when it's sunny outside because Jesus would totally be cool with you praising while you get a nice tan.
User avatar
Piter Lauchy
Time Waster
Time Waster
 
Posts: 1090
Joined: Thu Jan 07, 2016 1:33 am
Location: Bier und Wurst
Show rep
Title: Idk, someone give me one

Re: Saturated fats, polyunsaturated fats, and carbohydrates

Postby cmsellers » Thu Nov 29, 2018 5:48 am

Since most of the responses have focused on the carb angle, I would like to point out that there are three major takeaways from this book, only one of which is related to carbs.

  1. We should be eating more fat than we do, especially children and people trying to lose weight.
  2. Contrary to what we have been taught, saturated fats are healthy and most polyunsaturated fats are not. Note that this is actually more complex than I let on my OP. The evidence seems to suggest that short-chain polyunsaturated fats are good for us, at least in moderation, and that we should also be eating more omega-3 fatty acids, especially short-chain omega-3s of the sort found in fish. What we definitely should not be doing is eating lots of the long-chain omega-6 polyunsaturated acids found in most vegetable oils.
  3. And yes, the high-carb diet that the nutrition community and government have been pushing on us is likely the major cause of weight gain, diabetes, heart disease, and several other issues.

@Kivutar: Actually, zero starch in the diet is fine. The issues with an all-animal-products diet come from eating only muscle meat and only cooked. Eating the organs raw and/or eating green vegetables is enough to remedy that, but since I don't want to do those things, I'm keeping fruit in my diet, and I'm keeping some whole grains in my diet for now since they're a source of fiber. The big change I've decided to make for now is to be more liberal with the dairy and meat, and stingier with the whole grains and fruit. I will see how I am doing weight-wise and how I am feeling in a couple months, and reevaluate then.

Starch has been a major component of the diet of most humans since before we were humans. The hunter-gatherer diet ranges from nearly all meat (Inuit and Masai) to nearly all starch (Yanomamo), apparently without ill-effects on either front. However the Inuit and Masai have been studied more extensively than the Yanomamo, and Westerners have tried to replicate their diet, precisely because of how unhealthy their diet was presumed to be. The only study I know of on the Yanomamo found that their extremely low-sodium diet did not seem to be having negative blood pressure effects, but given that the salt-blood pressure hypothesis seems to be bullshit as well (but I've suspected this for awhile and don't think the effects of low-sodium diets are as damaging as low-fat diets), I'm not sure what this means. But given that the Yanomamo diet is mostly bananas, which may be high in resistant starch (green banana flour certainly is), and given that humans can evolve to adapt to dietary changes rather quickly, I will not believe that the Yanomamo diet is sustainable until it is studied in Westerners. I will say that the banana diet certainly does not seem like a diet I would want to eat.

Hunter-gathers averaged around 50/50 meat/starch in their diets, with some fruit and leafy vegetables as well, and while I've seen estimates on the majority of their calories being meat or starch, there is so much variation that I'm not sure there's necessarily one ideal diet for humans. Our farming ancestors absolutely did eat a diet which was mostly starch, but it's worth keeping in mind that refined starch and sugar are relatively new additions, and that our farming ancestors were generally shorter and suffered from a whole range of maladies that hunter-gatherers and pastoralists did not. However when you put those same hunter gatherers and pastoralists, and even farmers who've had less time to adapt to refined starches and sugars than sedentary Eurasians, they have even more health problems than we do.

When you also consider the fact that obese people see better weight loss and health results on ketogenic diets than moderate diets such as the Zone Diet (which is probably the closest of any fad diet to what I've been eating), which in turn show far better results than the low-fat, high carb "balanced" and "sensible" diet the USDA and AHA have been pushing for two generations now, I am led to conclude the following about starch:

  1. Starch is completely nonessential to our nutritional needs. There are essential amino acids and essential fatty acids, but there is no such thing as an essential carbohydrate. We need a very small amount of glucose, but our bodies can synthesize glucose from protein.
  2. We should eat refined starches (ie, white rice, white flour) as rarely as possible. The USDA says three or more servings a day is fine, and it absolutely is not.
  3. In excess, even most (possibly all) unrefined starches are awful for us.
  4. People whose ancestors had a history of eating starches and especially refined starches (Europe, North Africa, most of Asia) are better able to tolerate the ill-effects of excess starch than people without such a genetic history (Pacific Islanders, American Indians, North/Central Asians, and Sub-Saharan Africans), but we still haven't adapted to eat a diet as high in starch as the diet nutrition "experts" almost always advocate.
  5. If you want to lose weight fast, a ketogenic diet is probably the way to go, but given that it only takes ten grams of sugar, starch, or soluble fiber to break ketogenesis, most people living in Western dietary culture are going to have an immensely hard time sticking to it long term.
  6. In moderation, there's something to be said for eating some starch, as a source of fiber and variety if nothing else, some small amount of mostly-unrefined starch probably belongs in a healthy diet. Especially if you're trying to maintain your weight rather than lose weight.
  7. Not all starch is created equal, and we need both more research into the effects of different kinds of starch on the body and better food labeling which distinguishes various kinds of starch.

@Anglerphobe:
Were you on a completely ketogenic diet? Ketogenic diets are usually hell for the first few weeks from what I've read. However if you weren't on a ketogenic diet, your body is still burning glucose, so you would get a "high" from sugar and starch shortly after eating them.

@Piter:
That's sort of the point though. It's very hard to be healthy when nearly all the "experts" are recommending a diet which is both A. incredibly unhealthy, and B. very hard to stay full on, at least if you are the sort of person who listens to expert recommendations.
  • 3

User avatar
cmsellers
Back-End Admin
Back-End Admin
 
Posts: 9316
Joined: Sun Apr 14, 2013 7:20 pm
Location: Not *that* Bay Area
Show rep
Title: Broken Record Player


Who is online

Users browsing this forum: No registered users and 20 guests

cron