Protein is the most important macronutrient for anyone trying to build muscle. Without adequate amino acids from dietary protein, your body cannot synthesize new muscle tissue regardless of how hard you train.
The Science of Muscle Protein Synthesis
Muscle protein synthesis (MPS) is the process by which your body builds new muscle tissue. It's triggered by resistance training and, crucially, by the presence of amino acids (from dietary protein) in your bloodstream. The rate of MPS peaks about 24 hours after training and remains elevated for 24-48 hours. To keep this process going, you need regular protein feedings throughout the day.
How Much Protein Do You Need?
For muscle building: 1.6-2.2g per kg of bodyweight per day. That's 120-165g for a 75kg person. This is substantially higher than the RDA (0.8g per kg), which is designed to prevent deficiency, not optimize muscle growth. If you're in a calorie deficit (cutting), protein needs are even higher — up to 2.5g per kg to help preserve muscle mass.
Protein Per Meal
Your body can only use about 30-40g of protein in a single meal for muscle synthesis. Eating 100g of protein in one sitting doesn't produce 3x the synthesis of 33g — the excess is used for energy or stored. Spreading protein across 3-5 meals, with 25-40g per meal, optimizes the muscle protein synthesis response throughout the day.