A study out of the University of Illinois supports recent research touting the effects of a high-protein, low-carbohydrate diet plus exercise as the most effective regimen for achieving weight loss. This is one of the few investigations that have considered the role exercise plays in weight loss and altering body composition. The study team randomly assigned 48 women ages 40 to 56 to 1 of 4 regimens: a high-protein diet; a high-protein diet plus exercise; a high-carb diet; or a high-carb diet plus exercise. All diets were nutritionally sound, as the women consumed recommended amounts of fruits, vegetables, and dairy. Those in the exercise groups walked 30 minutes a day 5 times a week and included resistance/weight training. After 4 months, all the women lost a significant amount of weight and body fat and were able to reduce their caloric intake. The group that lost the most weight and fat and added lean muscle mass, however, was the high-protein diet plus exercise group. Those women reduced their body fat by 21.4%, compared with the women in the high-carb diet group, who decreased their body fat by only 12.8%. The high-carb group lowered their total cholesterol levels, including low-density lipoprotein cholesterol, more than the other groups. Women in the high-protein group had greater decreases in triglycerides, however, and maintained higher levels of high-density lipoprotein (HDL) cholesterol. Researchers concluded that women with high levels of triglycerides and lower levels of HDL cholesterol may benefit from the high-protein diet, while those with high cholesterol may benefit from the high-carb diet.
Ms. Farley is a freelance medical writer based in Wakefield, RI.