Researchers say low-carbohydrate diets more effective in weight management.

In a paper published in the Nutrition Journal, researchers from SUNY Downstate Medical Centre show that low-carbohydrate, high-protein diets can be expected to be more effective for weight loss than low-fat diets.

Their theory goes against long standing prejudices of the nutritional community, which for years have claimed that only calories count in the battle to lose weight.

"There are numerous examples of low-carbohydrate diets being more effective than low-fat diets with the same number of calories. It doesn’t always happen but it can happen," said Dr. Richard Feinman of the Department of Biochemistry, SUNY. "The nutritional establishment has been reluctant to accept this, because they say it violates the laws of thermodynamics. However, they have not really looked seriously at thermodynamics. If they had, they would see that these results are possible, and according to the second law of thermodynamics, are also to be expected."

Feinman and Fine reviewed the existing literature on studies that compared low-carbohydrate and low-fat nutritional approaches. In doing so, they found a sufficient number of reports in the literature to establish the existence of a metabolic advantage. Clinical studies from such well-established research facilities as Duke and Harvard, among others, were reviewed and analysed.

The researchers tabulated results from 10 studies, demonstrating that low-carbohydrate diets can lead to greater weight loss than isocaloric low-fat diets.

To explain this metabolic advantage, Dr. Feinman and Dr. Eugene J. Fine suggest that carbohydrates make an efficient fuel for the body, whereas protein does not.

The researchers stress that the human body is not a storage locker. They compare it to a machine, and the efficiency of the machine is controlled by hormones and enzymes, which are impacted by nutrients.

Carbohydrates increase insulin and other hormones that regulate enzymes which can lead to storing fat rather than burning fat.

The practical point is that getting rid of the idea that "a calorie is a calorie" opens the door for serious research into what kind of diets will be most effective and which people will benefit most.

http://biz.yahoo.com/prnews/040813/nyf088_1.html