Macronutrient considerations for the sport of bodybuilding

Entrez PubMed: "There is evidence that a relatively high protein intake (approximately 30% of energy intake) will reduce lean mass loss relative to a lower protein intake (approximately 15% of energy intake) during energy restriction. The higher protein intake will also provide a relatively large thermic effect that may aid in reducing body fat. In both the off-season and pre-contest phases, adequate dietary carbohydrate should be ingested (55-60% of total energy intake) so that training intensity can be maintained. Excess dietary saturated fat can exacerbate coronary artery disease; however, low-fat diets result in a reduction in circulating testosterone."

This is a very concise description of the importance and the quantity requirements for macronutrient intake, which application is of highest importance in the sport of natural bodybuilding.