Amino acids are the building blocks of proteins and play a vital role in metabolism, tissue repair, and maintaining muscle mass — especially on the keto diet, where protein helps preserve lean body mass in the absence of carbohydrates. Essential amino acids, such as leucine, isoleucine, and valine (BCAAs), support energy metabolism and physical endurance. A proper balance of amino acids promotes better recovery, appetite regulation, and overall health on a ketogenic lifestyle.