Jewish World Review May 8, 2003 / 6 Iyar, 5763

SLIM CHANCES: Study underscores benefits of high-protein diets

By Bev Bennett | If your diet leaves you thin but jiggly, perhaps you're not eating enough protein, which is essential to building and maintaining muscle. By eating more low-fat animal protein from beef, dairy foods, poultry, fish and eggs, you stay muscular while losing fat and pounds, says Don Layman, the lead researcher of a new diet study conducted at the University of Illinois at Urbana-Champaign.

Americans in general don't eat enough protein, and it may be a particular problem when you're trying to lose weight, says Layman, a professor of nutrition in the department of food science and human nutrition.

When you cut back on calories, your body can start burning muscle tissue for energy. If you don't build new muscle with protein, you're flabbier after you diet. Keeping your muscle tone is important for more than aesthetic reasons. Muscle helps the body burn more calories. The more muscle you have, the more calories you burn.

Layman emphasizes that animal protein is high in leucine, an amino acid that's key to muscle synthesis. Although you can get leucine from plant foods, you'd have to eat considerably more to get the same amount as you do from animal sources, he says. In the university study, Layman and his colleagues put 24 midlife overweight women on a 1,700-calorie diet for 10 weeks. All the women had the same amount of physical activity.

The control group followed a diet based on the Food Guide Pyramid from the U.S. Department of Agriculture (USDA), which emphasizes carbohydrates, including grains, whole grains, fruits, vegetables and a moderate amount of protein foods. The study group ate twice the amount of protein, about 0.73 gram of protein per pound of body weight. For example, a woman who weighed 137 pounds would be eating 100 grams of protein a day on the diet (see the sidebar for a list of high-protein, lean foods).

The volunteers also decreased their carbohydrate consumption by more than 25 percent, to 0.95 gram per pound of body weight. Using the same example, the woman would be consuming 130 grams of carbohydrate a day.

The foods the women on the moderately high protein diet were given met the National Cholesterol Education Program guidelines for heart-healthy eating. At the end of the study, both groups lost a similar amount of weight, about 16 pounds. However the higher protein group lost 2 pounds more of body fat and maintained 1 more pound of muscle mass than the control group.

In addition, the women in the study group were less hungry between meals, had more stable blood glucose levels and decreased their triglyceride levels. Since both groups lost about the same amount of weight, Layman's limited study isn't going to end the current debate about whether high-protein or high-carbohydrate diets lead to better diet results.

"I'm not out to say that a high-carbohydrate, low-protein diet is bad,'' he says. "I've proven that both are effective. In my perspective, I've expanded the tool box. I'm giving people another option to try that's safe and effective.''

To follow the diet, Donna Erickson, a dietitian at the university, suggests that you eat 3 ounces of lean protein for breakfast; 3-4 ounces at lunch and 5-6 ounces at dinner. An afternoon and a before-bed snack, such as a piece of string cheese or a glass of milk, complete the day's meals.

"This wasn't a sparse diet,'' says Erickson, who worked with Layman. "We didn't want people to get hungry.''

Erickson reports that the higher-protein volunteers were pleased with how they felt on the diet. "The women say they were more energetic than with their previous eating style, which was pretty much a high-carbohydrate diet,'' she explains. "They hadn't been eating high-quality carbohydrates.''

Layman's "Sensible Solution'' diet was funded by American beef producers; Kraft Foods; the U.S. Department of Agriculture and the Illinois Council on Food and Agricultural Research.

Bev Bennett is co-author of "The Dictionary of Healthful Food Terms.'' Comment by clicking here.


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