Okay, read Taubes' article in the New York Times, "What if it's all been a big fat lie?". That's ten years old, there has been research published since then, but nothing to change the basic conclusions.

I suggest reading it before the rest here!

The organizations are not "scientific." They are largely political creatures, and how they are funded can be an issue. If cholesterol is not the problem, what happens to the statin drug market? But I don't know that recommendations are driven by funding.

Taubes is a thorough science writer, a skeptic, and it is indeed science that he's interested in. He is not selling a diet.

Taubes covers the history of diet recommendations in the U.S. It's shocking.

Something brief: In 1957, the American Heart Association opposed Ansel Keys (the author of the epidemiological study that got the whole fat=bad thing going), with a 15-page report, saying there was no evidence for the fat/heart disease hypothesis. Less than four years later, a 2-page report from the AHA totally reversed that, and, according to Taubes, that report included a half-page of "recent scientific references on dietary fat and atherosclerosis," many of which contradicted the conclusions of the report, which recommended reducing the risk of heart disease by reducing dietary fat..

What happened? Did the science change that quickly? Read Taubes! (i.e, read the book, "Good Calories, Bad Calories." Taubes also has a recent book, less technical, more popular, I think, but I haven't read it.)

I could point to studies; the Atkins diet in particular has been studied independently, and it improves cardiac risk factors, it does not make them worse. Yet it's a high-fat diet. So what is the risk?

Yes. I'm arguing against a commonly-recommended diet. I'm suggesting that relying on these agencies and their recommendations, without understanding the science, is very dangerous.

Taube had written a book about salt, and when he was doing the research, he noticed nutritional "expert" after "expert" who had no clue how science works, who used extremely poor reasoning, conclusion-driven. And he noticed the same when he started working on fat.

When I started reading in the field, out of personal necessity, I could see it myself, really poor "science" being commonly asserted as if it were simple fact.

Such as "a calorie is a calorie." I.e., it's said there is no difference between fat calories and carb calories, and the claim of Atkins that fat had a "metabolic advantage" was allegedly preposterous, this would supposedly violate the laws of thermodynamics.

However:

1. various foods take different amounts of energy to metabolize, and some calories are excreted.

2. food calories are not thermodynamic calories, and this is not merely the "kilocalorie" thing, they are modified according to metabolic factors estimated from studies that were done about a century ago, and that may not be accurate under various dietary conditions.

3. carb metabolism (burning glucose) runs the body in a different way, and has behavioral effects, compared to fat metabolism. Appetite shifts (fat suppresses appetite, generally).

There never was good evidence that saturated fats increased cardiovascular risk, that was speculation from the highly flawed Keys study. It was thought "well, to really know will take very expensive trials, we can't do that, so why not reduce fat? It can't hurt!"

But it could and probably did hurt. Lower fat in the diet, you almost certainly raise carbs, and quite possibly increase obesity, diabetes, heart disease, and there is an effect on cancer, apparently.

Bottom line, the officially-recommended diets have very little science behind them.

This really is not the place to debate the issue. Read the literature! Taubes is an excellent door into it, the book GCBC is about a fourth footnotes.

Or look at the Wikipedia article Saturated fat and cardiovascular disease controversy, (Do not trust Wikipedia articles to be neutral. They frequently are not. Use them to find other sources.)

It's tempting to sit back and trust the official organizations. It's a lot of work to actually read the evidence. However, is this important?

I thought it was, like, my life depends on it.

The AHA is a $600 million/year organization. If fat/heart disease hypothesis is as wrong as it appears to be, they may have cost Americans, in damage to health, a great deal more than that. Now, consider what we know about human organizations. When they get it spectacularly wrong, but before there is absolute proof, do they back up easily?

No. Their business is to be the experts, remember that $600 million per year.