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.
Alex’s notes: Bodybuilders are the true epitome of leanness during their contest prep. They are able to push the limits of the human body and achieve body-fat levels barely above the essential fat required for life. They are also able to do this while maintaining significant physiques and muscle mass. Now, although there is nothing to be done about the metabolic adaptations that occur during this time (outside of drugs, that is), there are nutritional strategies that make the process as efficient as it can be. This brings us to the current review by Eric Helms, Alan Aragon, and Peter Fitschen that seeks to summarize the literature of contest preparation nutrition and supplementation in order to provide optimal recommendations for those undertaking such a feat. While the review at hand is focused on contest bodybuilders, its information is applicable to anyone who is relatively lean and looking to diet.
To start, a caloric deficit is required for fat-loss, but more aggressive dieting and being leaner in general increase the risk of lean-body-mass (LBM) loss. It appears that dieting for 2-4 months or longer yielding .5-1% of bodyweight lost weekly is optimal for LBM retention. Furthermore, as the availability of adipose tissue declines the likelihood of muscle loss increases, thus it may be best to pursue a more gradual approach to weight loss towards the end of the preparation diet compared to the beginning to avoid LBM loss.
Next up is macronutrients. Although most individuals can achieve a healthy weight just watching “what” they eat, achieving ultimate leanness (and even just getting below 10% for males or 20% for females) requires more tedious dietary habits. For protein, requirements may be greater when dieting and in leaner individuals, and should be set within the range of 2.3-3.1 g/kg of LBM. Carbohydrates are necessary to support performance in the gym and although a high protein diet can be effective for weight loss, a practical carbohydrate threshold appears to exist where further reductions negatively impact performance and put one at risk for LBM losses. Between 4–7 g/kg depending on the phase of training has been previously recommended, but the ultimate value will vary depending on the individual and the amount of calories they have available to divide up between nutrients. Finally, fat is necessary for optimal functioning of various hormones but since down-regulation of these hormones is inevitable when dieting, a lower end fat intake between 15-20% of calories can be deemed appropriate if higher percentages would reduce carbohydrate or protein below ideal ranges.
Nutrient timing and meal timing is another area of concern for the dieting athlete, as it can help spare LBM losses and boost gym performance. Overall, consuming adequate nutrients around training and spaced at least 3 hours apart to maximize the protein synthetic response seems prudent. The evidence collectively suggests that extreme lows or highs in meal frequency have the potential to threaten lean mass preservation and hunger control during bodybuilding contest preparation. However, the functional impact of differences in meal frequency at moderate ranges (e.g., 3–6 meals per day containing a minimum of 20 g protein each) are likely to be negligible in the context of a sound training program and properly targeted total daily macronutrition.
As for supplements, creatine (3-5g daily), beta-alanine, HMB, BCAAs, arginine, citrulline malate, glutamine, and caffeine may hold promise, but again, sound training and diet is more important.