Building muscle (hypertrophy) requires two things: resistance training stimulus and adequate protein. Nutrition is the other half of the muscle-building equation.

Muscle protein synthesis (MPS): The process of building new muscle tissue from amino acids. Triggered by exercise and dietary protein.

Leucine threshold: Leucine is the key amino acid that triggers MPS. Need ~2–3g leucine per meal to maximally stimulate MPS. Found in ~25–40g of high-quality protein.

Practical guidelines:

• Total protein: 1.6–2.2g per kg of body weight per day for muscle building
• Distribute evenly across 3–5 meals (~20–40g per meal)
• Post-workout protein within 2 hours (the "anabolic window" is wider than once thought)
• Prioritize complete protein sources: meat, fish, eggs, dairy, soy

Myth busted: The body does not have a strict 30g protein absorption limit per meal. It can absorb more — it just digests more slowly.

Reference:

Wikipedia: Muscle hypertrophy

https://en.wikipedia.org/wiki/Muscle_hypertrophy