 Diet has always been as important, if not more, as weight-training for bodybuilders.However, in his book "Heavy Duty Nutrition", Mentzer demonstrated that nutrition for athletes did not need to be nearly as extreme as the bodybuilding industry would lead one to believe.His recommended diets were well balanced, and he espoused eating from all four food groups, totaling four servings each of high-quality grains and fruits, and two each of dairy and protein daily, all year-round.