In order to achieve large gains in muscle mass along with significant body fat decreases, many hormonal events need to occur in the body. The amount of success that that can be achieved in these endeavors is determined by how much testosterone, growth hormone, and insulin are produced by the body and whether or not they are produced at the right times.
These events are affected to a large extent by the quality, timing, amount, and ratio of the macronutrients consumed on a daily basis. There are three major macronutrients that the human body needs in order to function properly: carbohydrates, protein, and fats.
The 3 Major Macronutrients: Carbs, Protein, & Fats.