Beyond boosting muscle growth, it also supports heart health, energy levels, and overall well-being. Protein may preserve muscle mass by:Providing amino acids : Protein supplies the the amino acids your body needs to maintain muscle during your weight loss journey. Improving cholesterol levels for specific groups : If you have a metabolic disorder, the effects of whey protein on cholesterol levels may be particularly pronounced. : If you have a metabolic disorder, the effects of whey protein on cholesterol levels may be particularly pronounced. Providing backup energy: While not your body's main source of energy, protein does contribute as an energy source.