Vegan protein sources are sh*t Meat Proteins are superior Why? Vegan proteins have less protein overall and, more importantly, less leucine—the key amino acid that triggers muscle growth. There are 9 essential amino acids we need from food, and leucine is the most important one for building and repairing muscle. Meat is the superior protein if you’re trying to gain muscle and lose fat because it keeps you full and helps you stay in a calorie deficit. It also has much higher levels of leucine Bot