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Hormones, Strength, and Fat

November 15, 2005 01:43 PM

A lot of people who are serious about being strong and lean eat high protein/low fat diets. They then must make up the calories from low fat intake by eating carbohydrate. They are taught that carbs are protein-sparing and release insulin, an anabolic hormone.

There are a lot of problems with this model in my view.

1. Most important, a diet of this kind was never part of the evolutionary past, nor is it seen in hunter-gatherers. Their diets are fairly high in fat and protein. What carbohydrate they eat is very complex and slow digesting and unlikely to promote an insulin response of any magnitude.

2. Insulin reduces GH response, so eating carbs reduces the rate of protein synthesis in the muscles. How can carbs be protein sparing when this is true? And protein is capable of eliciting its own insulin response, so why is it recommended to ingest the simple carbs that abound in protein supplements in order to elevate insulin? Elevated insulin is the last thing you want as it is the precursor to the metabolic cascade leading to ROS damage, obesity, high blood pressure, and accelerated aging.

3. It gets worse, at least from an evolutionary and systems perspective. A low fat diet combined with elevated carbs can deplete the pools of anabolic hormones and their substrates. These hormones are made from fats so a low fat diet may lead to reduced levels of anabolic hormones.

4. The three substance, macro model of nutrition is hopelessly oversimple and a poor guide to nutrition. Good nutrition covers the micronutrients that abound in natural foods and their interactions cannot be captured in a macro model.

5. A low fat diet promotes protein wastage because the body is put in a hormonal state where it becomes a poor metabolizer of fat and thus must resort to protein catabolism as a source of glucose. Eat a lot of carbohydrate and you become a carb burner, leaving all those triglycerides floating free in your blood stream and piling the fat onto your mid section from your high insulin level. You can't access this fat for energy and burn up your muscles instead.

6. I know you are looking for a study of this and there aren't that many. One that gets at these issues is in Int. J. Sports Med 2004 Nov: 25(8): 627-33. The researchers had five athletes and five non-athletes keep diet diaries before they began a high volume, high-intensity work out. Before the workout, the individuals with the higher fat intake had higher levels of anabolic hormones. After the workout, only the athletes showed this association of higher fat intake and higher anabolic hormones.

Not hard to see how this might be. High intensity exercise releases GH and makes you a fat burner. In the post exercise phase you replentish muscle glycogen through fat metabolism. Only the athletes had trained long enough to be conditioned to this reponse from hard exercise. And the ones who consumed more fat had a stronger anabolic response to the workout. Why not, they have adapted their GH response to the diet and activity and become good fat burners. They live nearer the hunter gatherer lifeway.

· Evolutionary Fitness

Comments

Posted by: Flower Online [TypeKey Profile Page] at September 12, 2006 3:35 AM

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