Protein is crucial for building muscle. Aim for about 0.8-1 gram of protein per pound of body weight, unless you're obese, in which case you should use your lean body mass. High protein intake has been shown to build more muscle, increase strength, regulate appetite, and preserve muscle while dieting. It's especially important when in a calorie deficit. Protein powders can be convenient for meeting protein goals, especially for those who struggle to consume enough protein through whole foods. Remember, protein is the most important macronutrient for building muscle.