[...] Pretty telling chart that J. Stanton of GNOLLS.ORG put together right here: The Lipid Hypothesis Has Officially Failed. Lot's of other great insight on that blog so have a look around. Here's a suggestion: Fat And [...]

How did they get this so wrong? Were there already some lobbies in place which had a lot to win in pushing high-carb, low fat foodstuffs? Or was their science just severely flawed?

[...] lipid hypothesis has failed and the myth of complex [...]

[...] This is about the lipid hypothesis which is the basis for the low-fat diet that’s made all Ame... [...]

OK, I went and looked up body mass index on Wikipedia and the *method* of calculating BMI has always been the same, BUT, what is termed "overweight" or "obese" has changed. So again, what we need is a chart that shows what percentage of the population has a BMI of ___ number or above. Maybe 25 and 35 might be good cutoffs for overweight and obese respectively, or 30 and 35.

[...] nunca provou nada, e falhou sempre nos principais estudos em melhorar a saúde em geral. Oficialmente, falhou, há que assumir o fracasso de [...]

JS,

I just listened to the first half of the Latest In Paleo podcast featuring you. I'll get back to it later, but so far, so good!

I really like your site and I'm enjoying the articles.
I know this post is a couple of months old, but I'm commenting anyway because I think there's more of interest regarding the paper you've sited.

I downloaded a copy of Divergent Trends in obesity and Fat Intake Patterns and gave it a read. It's fairly short. Here are some things I think might be worth pointing out:

To start with, here's the core observation. According to the data gathered for large cohort studies of impeccable pedigree, in the U.S. between 1977 and 1987 not only did the average fat intake decrease (down 11%) but total calorie intake as well (down 4%). At the same time, however, there was a huge jump in overweight and obesity. This, according to the authors, is a "paradox."

What's most interesting is what the authors conclude from the data. It's clear that they take the Lipid Hypothesis as gospel. They conclude that the only possible explanation for the weight gain is that everyone got more sedentary. They readily admit that there is no evidence for this, though they also argue that there's been no reliable measure of physical activity trends.

They site a study that claims "...the percentage of Americans who had a sedentary lifestyle remained stable..," IE: There's been no change in physical activity for Americans. They go on to suggest, however, that, though Americans may not be exercising less, they MUST have become significantly less active during the rest of their "non-leisure" day. A fancy way of saying that life must have gotten significantly easier for us physically or that we're just suddenly much lazier - the oft referenced "Glutton or Sloth" hypothesis. The data show that Americans don't seem to be gluttons. Since, however, they have gotten fatter anyway, then it must be that we've become more slothful. QED.

The authors try hard to hammer out the "paradox" with the blunt mallet of "energy in equals energy out." There's a great bit on the last page of the paper where they site another study in which subjects were put through 8 weeks of exercise and "unexpectedly" there was a drop of 60% in non-exercise-related physical activities. Yet, they aren't compelled to ask whether or not this suggests even the possibility that physical activity isn't the dominant causal factor in the rise of obesity. Or that there might be more going on here than can be reflected in a simple algebra equation.

Here's a telling quote:

Other researchers have suggested that "...a modern inactive lifestyle must play an important, and perhaps dominant, role in the development of obesity. It is likely that the reported high levels of sedentary lifestyle in the United States, which appear to be unchanged since 1986, do not accurately reflect trends in total physical activity, which may well have declined."

Noted also was the greater divergence in weight gain and calorie intake in women in their 50s and white men. The conclusion? They are becoming disproportionately less active. Might we suggest that, at least in the case of the middle-aged women, a tired pancreas and insulin-deaf cells might be a factor? Don't know. Just saying.

The last paragraph of the paper is also a gem. It begins:

"In summary, it appears that the efforts to promote the use of low-calorie and low-fat food products have been highly successful and have been in line with the objectives of the US Public Health Service."

So, the campaign to change the way everyone eats has worked! Everyone's eating less fat and fewer calories. Unless, however, the "objectives of the US Public Health Service" is to increase obesity and diabetes, I'm not sure how this can be said to be "in line."

The conclusion of the authors?
There's nothing wrong with the underlying assumption.
It's all our fault for finding creative and hidden ways to be sedentary!

If people are more sedentary it's because they are getting fat. Taubes makes a big deal of this. If you eat too many carbs, they will take the fat to storage and should you eat less, your activity level will go down.