Protein is the nutrient that is responsible for muscle building the most, getting enough amount of protein is key for growing and strengthening muscles.

 

It goes straight to muscle and helps it in its healing process after a workout, which later on makes them bigger and stronger

 

Taking in less amount of protein than needed, will slow progress when it comes to workouts, the muscles wont be able to recover properly which means the body is not going to be ready for the next workout.

 

It's also important to remember that getting too much protein doesn't mean the muscle will grow bigger, when the muscles reach the maximum amount of protein they can storage, the rest will be kept in the body as fat.