Protein shakes have long been associated with weight gain—athletes use them to gain muscle and body-builders attribute their unmistakable bulk to high protein intake. So it’s a little strange that companies are now peddling protein shakes for weight loss—the exact opposite of what they’re known to do. Surprisingly, there’s real science supporting this claim. So how does it work?
If you’ve been reading up on weight loss, you’re probably familiar with fat and muscle densities. Fat is less dense than muscle, which means it weighs less while taking the same amount of space. So the more muscle you have, the smaller you will be while remaining in a healthy weight range. In addition, muscle burns more energy than fat, so if you have more muscle in your body, any physical activity you do will be much more effective.
Protein helps you build muscle mass and rebuild muscles that get worn out from exercise. Protein shakes, usually made with soy protein powder containing a range of other nutrients, are a great way to get your daily dose without taking in the calories that come with common food sources such as meat and poultry. They are often used as breakfast “power drinks,” combined with milk or fruit to create a smoothie.
Does it work? Research shows that it does—in a recent study, people who regularly drank protein shakes lost four to six pounds per month. The catch is that these people also got regular exercise and stayed on a low-calorie diet. This makes sense because protein builds muscle—it doesn’t do anything about the fat. Without enough exercise, you end up with a lot of muscle under a lot of fat. Aerobic exercise such as running or cycling, combined with weight lifting or other forms of strength training, can help you take care of that.
Doctors recommend about one gram of protein a day for every pound of weight. Not everyone can get this much protein in just three meals, however—especially if they are watching their calories. This is where protein shakes come in handy. Of course, if you can get your daily protein from healthy dietary sources, that’s all the better.
Protein shake powders come in all forms, some of them pretty straightforward and others laced with other nutrients and flavors. If your goal is long-term weight loss, the fewer the added ingredients, the better. Your best bet is to consult your doctor and have him or her recommend a brand, as well as the right dosage and accompanying weight loss program.