Like many young men, my 20-something sons guzzle whey shakes as a way to add weight, with the goal of getting bigger and stronger. So you may be surprised—even skeptical—when I tell you that whey also can help with weight loss.

I kid you not. A new study published in The Journal of Nutrition provides proof, showing that whey protein supplementation helped overweight and obese people drop unwanted pounds and trim belly girth.

What’s more, whey can help you keep weight off for good. That’s because protein is one of the keys to sustainable weight loss and weight management, I heard from Chris D’Adamo, PhD, a nutritional research scientist at the University of Maryland School of Medicine in Baltimore.

The pluses of protein: Consuming sufficient protein is an important weight-control strategy. For one thing, protein increases satiety—you feel less hungry after eating protein than after eating carbohydrates or fats, so you’re less likely to feel deprived and blow your diet. Also, protein is more thermogenic than carbs and fats, meaning that your body tends to burn it off rather than store it as fat. Protein promotes lean muscle mass, too, which improves metabolism—so you use up more calories without doing anything extra. And there’s no need for women to worry about winding up with bulging muscles or a bulked-up appearance, Dr. D’Adamo said. Instead, protein simply promotes a higher muscle-to-fat ratio that results in a healthier body composition and easier weight management.

Why whey? Whey protein is a derivative of milk and contains all of the essential amino acids that your body cannot produce on its own. Compared to other protein supplements that have been studied, such as soy and casein (another milk protein), whey is a clear winner for weight control and for overall good health. That’s because whey…

  • Increases levels of satiety-boosting hormones, such as leptin and cholecystokinin, more than other proteins do. “It’s tough to lose weight when you’re starving yourself and you’re hungry all the time. Whey helps prevent that situation of persistent hunger,” Dr. D’Adamo said.
  • Has the highest bioavailable value among proteins, which means that our bodies can easily absorb and use it.
  • Improves insulin sensitivity, thus lowering the risk for metabolic syndrome, diabetes, coronary artery disease and stroke.
  • Stimulates production of glutathione, an antioxidant that improves liver efficiency, allowing the body to clear toxins and make better use of nutrients.
  • Contains 10% to 15% immunoglobulins, which are known to enhance immune system activity.
  • Is easy to digest. Even people who have problems with lactose (a sugar found in milk) usually can tolerate whey protein. Whey also contains little or no casein, a milk protein that also can cause digestive upset. However, Dr. D’Adamo noted that people with lactose or casein intolerance should initially consume small amounts of whey to test their tolerability.

    • Patients with liver or kidney problems who have been told to monitor their protein intake should check with their doctors before taking any protein supplement. Except for people with a milk allergy, who should avoid whey altogether, whey protein generally is safe.

    Yummy ways to add whey to your diet: Whey protein powder is sold at health-food stores, drugstores and online. Options include whey concentrate, which is more economical…and whey isolate, which goes through an extra filtering step to remove more fat and carbs (in the form of lactose) and thus may be preferable for people with lactose or casein intolerances who are using whey as a weight-loss aid.

    One or two servings of whey protein per day should be an appropriate amount for the average woman who wants to lose weight, Dr. D’Adamo said. A one-tablespoon serving contains about 40 calories. Breakfast is a great time to consume your whey because it helps suppress hunger for hours afterward. You also can have some whey about an hour before exercising—it will provide an extra energy burst and help maximize the body-composition benefits of your workout.

    Combine your whey powder with the cold or hot liquid of your choice, following label directions. Easy recipe ideas…

  • Mix whey powder with plain water for the lowest-calorie protein drink and a neutral taste. For a tastier beverage, add your favorite drink-flavoring product—for instance, Mio Liquid Water Enhancer or Crystal Light lemonade powder.
  • For a smoothie, blend whey powder with milk or juice…berries, bananas or other fruit…and ice.
  • Stir whey powder into hot cereal before cooking…or add to soups or stews before serving.