Thursday, June 2, 2011

Eat Fat, Stay Healthy

With the memory of Memorial Day cheeseburgers and bratwursts still lingering, many of us may be relieved to hear that a new study suggests that a meaty, high-fat, Atkins-style diet can do more than contribute to rapid weight loss. It may also be less unhealthy for the heart than many scientists had feared — provided you chase the sausage with a brisk walk.

What's the news?  Another group on a high fat diet fares well?  Hardly.  What's news is this is commented on with a fairly even handed tone in the NYT.
“It took people less time to lose 10 pounds” on a high-fat diet-and-exercise program, about 45 days on average, than the 70 days it took for those who exercised and followed a high-carbohydrate, low-fat diet constructed using guidelines from the American Heart Association, said Kerry J. Stewart, director of clinical and research exercise physiology at Johns Hopkins University School of Medicine and lead author of the report. And at least in the short term, there were no apparent harmful effects. 

Here's where the article goes where most mainstream articles go when discussing science and food - to the junk bin:
To date, however, scientific data have been inconsistent. Some studies have reported that such diets contribute to cardiovascular disease, while others found no increased risk
Show me those studies, and I'll show you that the "studies" they cite are observational studies, which as most of you know, is only useful for establishing a hypothesis (really, only useful for establishing a baby hypothesis, a conjecture).  When tested via intervention study, high fat diets virtually always win, as is the high fat diet in this still ongoing study.

These comments can only be considered amusing, though:
And like most of the recent studies about the health effects of low-carbohydrate diets, “these are very short-term results,” said Dr. Dena Bravata, an internist and research associate at the Center for Primary Care and Outcomes Research at Stanford University, who was not involved with this experiment but has conducted dietary studies. “Those on the high-fat diets showed no harmful impacts” after 45 days or so, she said. “But what about in 5 or 10 years, if they remain on the diet?”

Where was all this scientific rigor and skepticism about the long term impacts of diets when the government and many non profits - like the AHA and ADA - jumped "whole hog" on the low fat fad diet?  If there's one thing that's certain in the science of diet and health it is that there was no scientific basis or long term evaluation of the effects of eliminating fat from the diet and substituting carbohydrates.  And there still is not!

Interestingly, one of the conjectures Gary Taubes introduces in Good Calories Bad Calories, and Why We Get Fat, is that those on a high carb diet will exercise less when in caloric restriction, because low fat low cal low protein diets induce the starvation response much more quickly than protein adequate and fat adequate diets.  In other words, they get lazy because of their diet.  The same thing happens with a high carb diet which is not calorie restricted when people exercise - if the exercise puts them into caloric restriction, they will eat more.  

Lucky for us, we don't need a billion dollar long term study to evaluate the health impact of a high fat, adequate protein, carb restricted plan.  Give yourself an N=1 experiment, which will be more convincing than any number of NYT articles.

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