Warner loves whey protein because of its superstar ingredient, the amino acid leucine. “Leucine helps prevent muscle loss, and triggers a greater loss of belly fat. It takes energy from rich fat cells and gives it to undernourished muscle tissue.” While leucine is found in other food sources, whey protein contains more leucine than milk, egg protein or soy protein,” says Warner in her book, 10 Pounds in 10 Days.
One 2008 study, published in the journal Nutrition & Metabolism, found that when subjects followed a reduced calorie diet and ingested a whey protein supplement twice a day, they lost significantly more body fat than those that only reduced their caloric intake. While both groups lost weight (about the same amount), the whey protein appears to have helped the participants improve their body composition in addition to losing weight – those who ingested it twice a day lost more fat and less muscle mass that those who didn’t.
Your daily game plan: Mix up a protein shake with one scoop of whey protein isolate and 6-8 ounces of water and drink it 20 minutes before breakfast and 20 minutes before dinner (200 calories for both), in place of your mid-morning snack (like that scone from Starbucks) to save 260 calories, or 2.2 pounds this month.