Protein is critical for weight management because it plays a key role in muscle repair, growth, and retention. Consuming adequate protein can enhance feelings of satisfaction and fullness, helping to control appetite and reduce overall calorie intake. High-protein diets can also promote a higher metabolic rate since protein requires more energy to digest than fats or carbohydrates. Therefore, including sufficient protein in one's diet is essential not only for building muscle but also for maintaining a healthy body weight.