UW study says protein packs weight-loss punch

Despite the recent criticism, the Atkins diet may have been right -- at least on one level.

A recent UW study shows that the low-carb diet trend tended to work - not because of the low carbohydrate intake, but because it forced its followers to eat more protein. This extra protein helps dieters curb their appetites, resulting in lower daily caloric intakes.

UW physician David Weigle and his team tracked 19 middle-aged overweight men and women as they followed a 16-week diet. For the first two weeks, dieters tried to maintain their body weight by receiving 15 percent of their calories from protein, 35 percent from fat and 50 percent from carbohydrates. The percentage of fat was cut and protein was boosted over the next two weeks.

For the last 12 weeks, dieters were allowed to eat as many calories as they wanted, as long as they stuck to the percentages of calories from the third and fourth weeks. During the last 12 weeks, calorie intake decreased at about 450 calories per day and ended in an 11-pound weight loss.

The study's participants expressed an unusual feeling of fullness during the last 12 weeks and metabolic rates and hormonal responses were unable to explain this feeling. Researchers pointed to protein as the appetite suppressant, although they are unsure as to the reason it works so well.