By now, many have heard of the latest "study." Oh, sure. It's already in the news.
We randomly assigned 811 overweight adults to one of four diets; the targeted percentages of energy derived from fat, protein, and carbohydrates in the four diets were 20, 15, and 65%; 20, 25, and 55%; 40, 15, and 45%; and 40, 25, and 35%. The diets consisted of similar foods and met guidelines for cardiovascular health. [emphasis added]
That emphasis hides a lot of sin, I'll bet. Well, no need to guess, as they provide a reference for such guidelines:
...consume a diet rich in vegetables and fruits; choose whole-grain, high-fiber foods; consume fish, especially oily fish, at least twice a week; limit intake of saturated fat to <7% of energy, trans fat to <1% of energy, and cholesterol to <300 mg/day by choosing lean meats and vegetable alternatives, fat-free (skim) or low-fat (1% fat) dairy products...
No wonder "high fat" is only 40%, and I'll bet they had a tough time getting even to that level. If I recall correctly, the average American diet is already about 30% from fat, so what are they showing? They certainly aren't emulating the Tokelauans at 50% saturated fat, or anything. Massai, Inuit? Forgetaboutit.
Well, I'm not going to spend a lot of time on this, because it's just ridiculous (with a shout out to: Frank M. Sacks, M.D., George A. Bray, M.D., Vincent J. Carey, Ph.D., Steven R. Smith, M.D., Donna H. Ryan, M.D., Stephen D. Anton, Ph.D., Katherine McManus, M.S., R.D., Catherine M. Champagne, Ph.D., Louise M. Bishop, M.S., R.D., Nancy Laranjo, B.A., Meryl S. Leboff, M.D., Jennifer C. Rood, Ph.D., Lilian de Jonge, Ph.D., Frank L. Greenway, M.D., Catherine M. Loria, Ph.D., Eva Obarzanek, Ph.D., and Donald A. Williamson, Ph.D. -- hey, guys & gals; enjoy).
Simply A few points:
- There's no such thing as a "low fat diet." They're all high fat diets if fat loss is the goal.
- The lowest carbohydrate intake of all the diets was a whopping (yea, I can do the media hype, too) 35%. Presuming an average 2,500 kcal intake per day, that's about 220 grams of carbs -- not "low carb" by any means. So, this is merely a comparison between various moderate to high carb approaches -- approaches that leave insulin high and fat mobilization low.
- The highest fat intake is only 40%. A true high fat diet is 60%+ of energy from fat. You can't go above about 35% from protein, and that's pushing it (25% is more realistic). Simple: protein remains about the same, and the tradeoff is between carbs and fat. This study was heavily weighted in favor of carbs, particularly when one considers that carbs hammer insulin and fat has little to no effect. High insulin = no fat mobilization.
In conclusion, they proved that all diets with excess carbohydrate are crap and deliver virtually no results for most people. Hopefully, Dr. Eades will take this up. Stephan, at Whole Health Source, hadn't seen it until I emailed him. He laughed, of course, and might take it up.
I'll stay tuned.
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I found out about this study via a particularly awful article on it in the Denver Post yesterday. The study was bad, but the DP reporting on it was even worse. I just posted my own fisking of it, quoting you a bit:
http://www.dianahsieh.com/blog/2009/02/worthless-study-worthless-reporting.shtml
Thanks, Diana
If carbohydrates are so unhealthy, why is the traditional Japanese diet found to be so healthy? It’s loaded with carbs. Then there is the Mediterranean diet which is high in fat and carbs. I don’t think any one macronutrient is the enemy here. I think any diet that emphasizes whole pure foods, concentrates on veggies, and avoids refined carbs and trans fat will be healthy.
The Japanese diet isn’t “loaded with carbs” as much as it is a low caloric intake. I lived in Japan for five years. And don’t forget, the longest lived people — Okinawan Japanese — use lard as their primary cooking fat.
Anyway, I don’t believe carbs, per se, are the ultimate bad, just certain kinds like refined and processed foods high in sugar, grains, and vegetable oils.
Indeed, I have said for a long time that a healthful Paleo diet can be anything from the high carb diet of the Kitavans (based on starchy tubers) to the 80-90% animal fat diet of the Innuit and almost zero carbs.
What we’re about is finding the optimal diet, which likely exists somewhere between those two extremes.
In the end: eat Real Food and get lots of sun or vitamin D supplementation and you will likely thrive in good lean health.
Peter had some inof on the japanese diet vs the SAD (standard american diet) of the ’60s, not exactly what one would suspect.
http://high-fat-nutrition.blogspot.com/2009/10/sad-vs-traditional-japanese-diet.html
http://high-fat-nutrition.blogspot.com/2009/10/sad-vs-traditional-japanese-diet-2.html
http://high-fat-nutrition.blogspot.com/2009/10/more-from-japan.html