1.6-2.2g per kg of body weight per day for muscle building. This is significantly more than the basic RDA (0.8g/kg) which covers minimum health, not muscle growth. Timing matters too: 25-40g protein per meal is optimal for maximizing muscle protein synthesis.

For healthy individuals, high protein diets (up to 3g/kg) appear safe in studies. The main risk is calorie displacement — very high protein intake leaves less room for carbs and fat, potentially affecting energy and performance. For those with kidney disease, high protein intake does require medical guidance.