It’s theorized that because untrained individuals are further from their genetic limit for muscle mass, they may be able to gain muscle faster than trained individuals, and thus would benefit from a larger energy surplus.[1] Supporting evidence for this statement comes from an 8-week randomized controlled trial in untrained men that performed resistance exercise and added a 2,000 kcal supplement to their diet.[2] The participants gained a significant amount of fat-free mass (2.9–3.4 kilograms) without changes in fat mass.
In trained individuals, a substantial energy surplus seems to disproportionately increase fat mass, without further benefiting muscle gain. An 8–12 week weight-gain intervention in elite athletes found that a large energy surplus (600 kcal per day) produced a similar increase in lean body mass as an ad libitum diet that featured a modest energy surplus (by 1.7 kg vs. 1.2 kg),[3] but fat mass significantly increased with the large energy surplus (by 1.1 kg, vs. 0.2 kg for the modest surplus).
A 4-week trial in competitive male bodybuilders reported similar findings. The group consuming “higher amounts of energy” (6,100 kcal per day) gained more muscle mass than the group consuming “moderate amounts of energy” (4,500 kcal per day): 1.0 kilograms vs. 0.4 kilograms. However, the group consuming “higher amounts of energy” also gained considerably more body fat: 1.2% (a relative increase from baseline of 7.4%) vs. 0.1% (a relative increase from baseline of 0.8%).
Based on the available evidence, it’s recommended that individuals interested in muscle gain consume a hypercaloric diet containing 10%–20% in excess of that s required to maintain body weight, and that advanced lifters aim for the lower end of this range.[1] In practice, this corresponds to a targeted weight gain of about 0.25%–0.5% of body weight per week.
References
- ^Iraki J, Fitschen P, Espinar S, Helms ENutrition Recommendations for Bodybuilders in the Off-Season: A Narrative ReviewSports (Basel).(2019 Jun 26)
- ^Rozenek R, Ward P, Long S, Garhammer JEffects of high-calorie supplements on body composition and muscular strength following resistance training.J Sports Med Phys Fitness.(2002-Sep)
- ^Garthe I, Raastad T, Refsnes PE, Sundgot-Borgen JEffect of nutritional intervention on body composition and performance in elite athletesEur J Sport Sci.(2013)