How Weight Loss Products Really Work.

Protein can reduce hunger (thereby decreasing the calories you consume), help you preserve muscle as you lose weight, and help your body build more muscle, particularly if you include strength training in your fitness routine, says Richard Kreider, Ph.D., professor and chair of the Department of Health, Human Performance, and Recreation at Baylor University in Waco, Texas. Muscle burns more calories than fat and also helps you look trimmer, Kreider says, so strength training three times a week is a good addition to any weight-loss program.

A six-month study of 65 overweight and obese people published in 1999 in the International Journal of Obesity compared two low-calorie diets: one with 12 percent of calories from protein (which mirrors the federal recommendation for protein consumption) and one with 25 percent of calories from protein. Those who ate more protein lost more weight. The subjects did not exercise.

EFFECTIVE DOSE FOR WEIGHT LOSS

Take 40 to 50 g of protein powder a day, in the form of two shakes, and combine them with three small meals, Kreider says. Drink one shake mid-morning and another an hour before dinner, which will control your appetite at common craving times. To make sure you don't eat too many calories, reduce portion sizes at meals by a quarter to a third, Kreider says. This plan is safe for long-term use, he adds.

To make a shake, mix 20 to 25 g of protein powder and 12 ounces of water or milk. (Most experts we consulted recommend whey powder, a protein derived from milk, but if you're lactose intolerant, try soy powder.) For flavor, add some fruit, like a banana or a half-cup of berries.