The popularity of natural bodybuilding is increasing; however, evidence-based recommendations for it are lacking. This paper reviewed the scientific literature relevant to competition preparation on nutrition and supplementation, resulting in the following recommendations. Caloric intake should be set at a level that results in bodyweight losses of approximately 0.5 to 1%/wk to maximize muscle retention. Within this caloric intake, most but not all bodybuilders will respond best to consuming 2.3-3.1 g/kg of lean body mass per day of protein, 15-30% of calories from fat, and the reminder of calories from carbohydrate. Eating three to six meals per day with a meal containing 0.4-0.5 g/kg bodyweight of protein prior and subsequent to resistance training likely maximizes any theoretical benefits of nutrient timing and frequency.
However, alterations in nutrient timing and frequency appear to have little effect on fat loss or lean mass retention. Among popular supplements, creatine monohydrate, caffeine and beta-alanine appear to have beneficial effects relevant to contest preparation, however others do not or warrant further study. The practice of dehydration and electrolyte manipulation in the final days and hours prior to competition can be dangerous, and may not improve appearance. Increasing carbohydrate intake at the end of preparation has a theoretical rationale to improve appearance, however it is understudied. Thus, if carbohydrate loading is pursued it should be practiced prior to competition and its benefit assessed individually. Finally, competitors should be aware of the increased risk of developing eating and body image disorders in aesthetic sport and therefore should have access to the appropriate mental health professionals.
The popularity of natural bodybuilding is increasing rapidly. In the United States, over 200 amateur natural (drug tested) bodybuilding contests occurred during 2013 and the number of contests is expected to increase in 2014 . Preparation for bodybuilding competition involves drastic reductions in body fat while maintaining muscle mass. This is typically achieved through a decreased caloric intake, intense strength training, and increased cardiovascular exercise. Competitors partake in numerous dietary and supplementation strategies to prepare for a contest. Some have a strong scientific basis; however, many do not.
Therefore, the purpose of this article is to review the scientific literature on topics relevant to nutrition and supplementation for bodybuilding competition preparation. Dietary modifications during the last week to enhance muscle definition and fullness (peaking) and psychosocial issues will also be covered. Ultimately, evidence-based recommendations will be made for nutrition, supplementation, and “peak week” strategies for natural bodybuilders. As a final note, this paper does not cover training recommendations for natural bodybuilding and the training methodology used will interact with and modify the effects of any nutritional approach.