We all know adequate protein (especially after a workout) is key to building and repairing muscles, but a high-protein diet may also be the secret to consistent weight loss. In fact, research has shown that doubling your protein intake can help you drop pounds without losing muscle mass. In one study, published in The FASEB Journal, researchers put 39 patients on a weight-loss regimen over 31 days; at first, all participants were on the same diet to maintain their current weight. After 10 days, they were split into three groups following calorie-restricted diets: those who ate the US-recommended daily allowance (RDA) of protein, those who ate twice the RDA of protein, and those who ate three times the RDA of protein. The participants exercised accordingly in order to lose an average of two pounds a week. The researchers found that those who ate double the protein were able to lose fat without losing muscle mass while exercising on the diet. The participants who ate triple the amount of protein didn't experience any more weight loss than the double group.
If you're trying to lose weight, losing muscle mass is exactly what you shouldn't be doing, since muscle burns more calories. While the group was small, this well-controlled study shows that if you're healthy and active, upping your protein intake while restricting overall calories may be the way to go for short-term weight loss, the researchers say, even though they note you should still follow a balanced diet in the long run.
The RDA of protein varies depending on how much you weigh and how active you are, but as an example, the RDA for a 130-pound active woman is 77 grams, meaning according to this study, you should aim for 144 grams of protein each day if you are trying to lose weight. Check out this table of the US RDA of protein for women to help you figure out how much you should eat — double the number and see if it helps your weight-loss goals.