40-30-30 Diet
40-30-30 Diet Twice as Effective
(40% Carbohydrates - 30% Protein - 30% Fat)
New research suggests a diet higher in protein and lower in carbohydrates than currently recommended may help people maintain desirable body weight and overall health. Specifically, it focused on the type of food that helps maintain sufficient muscle mass so a person can efficiently expend energy to maintain a healthy body. This research was presented at the Federation of American Societies for Experimental Biology in Orlando in April 2003.
For 10 weeks, 24 mid-life women all above ideal weight ate 1,700 calories-a-day diets. One group ate according to the USDA Food Guide Pyramid - 55 percent carbohydrates, 15 percent protein and 30 percent fat. The experimental group ate a modified daily diet of 40 percent carbohydrates, 30 percent protein and 30 percent fat.
The average weight loss of all the women was virtually identical (about 16 pounds). Further analysis, however showed a startling difference for the 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.
"The protein diet was twice as effective," said Dr. Donald Layman, a professor of nutritional science at the University of Illinois. "Women eating the lower protein (higher carbohydrate) 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 studies in Dr. Layman's lab.
This study also found higher levels of thyroid hormones in women who ate the higher protein diet, suggesting a higher rate of metabolism. Protein-eaters also experienced a significant decline of overall triglycerides and a slight rise in HDL ("good" fat).