The average weight loss of all the women was virtually identical (about 16 pounds). From there, however, there were startling differences for women who ate the higher protein diet. They lost 12.3 pounds of body fat and just 1.7 pounds of muscle mass, a 7-to-1 ratio. Those who stuck to the food pyramid diet lost 10.4 pounds of body fat and, more significantly, 3 pounds of muscle mass a ratio of 3.5 to 1.

"The protein diet was twice as effective," Layman said. "Women eating the lower protein diet were less capable of burning calories at the end of the study as when they started it. We believe this is the effect of more protein, particularly the increased amount of leucine (an essential amino acid found in protein) in the diet." (Leucine's effect has been documented in several animal studies in Layman's lab).

The study also found higher levels of thyroid hormones among women who ate the protein diet, suggesting a higher rate of metabolism. Protein-eaters also experienced a significant decline of overall triglycerides (fat in the blood) and a slight rise in HDL (the desirable component of cholesterol).

'"/>

Contact: Jim Barlow
b-james3@uiuc.edu
217-333-5802
University of Illinois at Urbana-Champaign
2-Apr-2001