Taking extra protein supplements can lead to greater muscle growth only if your total daily protein intake is less than 1.6 grams per kilogram of body weight. If you already consume more than this amount, additional protein supplements do not result in further muscle growth.

If you're lifting weights and want to build muscle, eating at least 1.6 grams of protein per kilogram of your body weight every day is the most important thing — and eating even more protein (like 0.5 extra grams per kg) helps you gain a little more muscle on top of that.

If you're lifting weights and want to build muscle, eating at least 1.6 grams of protein per kilogram of body weight every day is the biggest factor that helps — more protein means better results, and when you eat it doesn't matter as much.

Taking HMB supplements does not significantly increase muscle growth in people who already eat enough protein, but might slightly affect muscle growth when calorie intake is very low or training intensity is extremely high.

If you eat enough protein (like 25g per meal), your muscles will grow even if you eat almost no carbs—carbs aren’t needed for building muscle.

In people who regularly lift weights, taking extra protein or essential amino acids can slightly increase muscle thickness—by about 1 to 2 millimeters—if their daily protein intake is under 1.6 grams per kilogram of body weight or if a single meal contains less than 2 to 3 grams of leucine. Beyond about 2.0 grams per kilogram per day, additional protein does not lead to further muscle growth.