Low-carb diets are among the most popular for losing bodyfat. Some critics contend, however, that much of the weight lost on them consists largely of water, since the diet leads to rapid breakdown of stored carbohydrate in the body’i.e., glycogen’which is stored with 2.7 grams of water per gram. Critics say that decreasing carbs too much favors excessive muscle protein breakdown.
Researchers from Ball State University in Indiana tested the body-composition effects of low-carb diets in 10 healthy men of normal weight. The subjects ate a diet that was less than 10 percent carbs, high in saturated fat and moderate in protein for six weeks. All subjects were encouraged to eat enough daily calories to supply sufficient energy, but diet compliance was determined by measuring ketones in blood and urine. Ketones are by-products of fat metabolism known to rise during low-carb diets.
The results showed that both fat mass and fat percentage were reduced at the three- and six-week points of the diet. Lean mass was unchanged at the three-week point, but by the six-week point it had increased. Thus the study shows that low-carb diets promote fat loss while also promoting muscle gains. IM