Of all the nutrients you eat, protein does the most heavy lifting when it comes to losing weight and keeping it off — and most people don't eat nearly enough of it.
Here's what makes protein special. First, your body uses a lot of energy just to digest it. About 20–30% of the calories in protein get burned during digestion itself. That means a 300-calorie serving of chicken has a much lower net calorie impact than a 300-calorie serving of bread.
Second, protein keeps you full. It triggers hormones that tell your brain you're satisfied and suppresses ghrelin, the "hunger hormone." Fewer hunger signals means fewer unplanned snacks.
Third, protein protects your muscle. When you're eating less to lose weight, your body can start breaking down muscle for fuel. Eating enough protein prevents this. More muscle means a higher metabolism — so the weight you lose is more likely to stay off.
Nutrition experts recommend about 1.2 to 1.6 grams of protein per kilogram of body weight per day. Good food sources include eggs, chicken, fish, Greek yogurt, cottage cheese, lentils, edamame, and tofu.
Building every meal around a protein source is one of the most practical strategies in nutrition.