In three out of six studies of male and female athletes, negative energy balance (losses of 0.02% to 5.8% body mass; over five 30-day periods) was not associated with decreased performance. In the remaining three studies where decrements in both anaerobic and aerobic performance were observed, slow rates of weight loss (0.7% reduction body mass) were more beneficial to performance compared to fast (1.4% reduction body mass) and one study showed that self-selected energy restriction resulted in decreased hormone levels.

• Grade I means there is Good/Strong evidence supporting the statement;
• Grade II is Fair;
• Grade III is Limited/Weak;
• Grade IV is Expert Opinion Only;
• Grade V is Not Assignable.
• High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
• Moderate (B) means we are moderately confident in the effect estimate;
• Low (C) means our confidence in the effect estimate is limited;
• Very Low (D) means we have very little confidence in the effect estimate.
• Ungraded means a grade is not assignable.

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  • Artioli GG, Iglesias RT, Franchini E, Gualano B, Kashiwagura DB, Solis MY, Benatti FB, Fuchs M, Lancha AH Jr. Rapid weight loss followed by recovery time does not affect judo-related performance. J Sports Sci. 2010; 28 (1): 21-32.
  •  Garthe I, Raastad T, Refsnes PE, Koivisto A, Sundgot-Borgen J. Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. Int J Sport Nutr Exerc Metab. 2011;21(2):97-104. 
  • Garthe I, Raastad T, Sundgot-Borgen J. Long-term effect of weight loss on body composition and performance in elite athletes. Int J Sport Nutr Exerc Metab. 2011; 21: 426-435.
  • Maestu J, Eliarim A, Jurimae J, Valter I, Jurimae T. Anabolic and Catabolic Hormones and Energy Balance of the Male Bodybuilders During the Preparation for the Competition. J Strength Condition Res. 2010; 24 (4): 1,074-1,081.
  • Mettler S, Mitchell N, Tipton KD. Increased protein intake reduces lean body mass loss during weight loss in athletes. Med Sci Sports Exerc. 2010; 42 (2): 326-337.
  • Paoli A, Grimaldi K, D'Agostino D, Denci L, Moro T, Bianco A, Palma, A. Ketongenic diet does not affect strength performance in elite artistic gymnasts. J Internat Soc Sports Nutr. 2012; 9: 34-43.

Over periods of four to 12 weeks, increasing protein intake during hypocaloric conditions maintains lean body mass (LBM) in male and female resistance-trained athletes. When adequate kcal are provided or weight loss is gradual, an increase in LBM may be observed.

• Grade I means there is Good/Strong evidence supporting the statement;
• Grade II is Fair;
• Grade III is Limited/Weak;
• Grade IV is Expert Opinion Only;
• Grade V is Not Assignable.
• High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
• Moderate (B) means we are moderately confident in the effect estimate;
• Low (C) means our confidence in the effect estimate is limited;
• Very Low (D) means we have very little confidence in the effect estimate.
• Ungraded means a grade is not assignable.

• Detail
• Quality Rating Summary
  For a summary of the Quality Rating results, click here.
• Worksheets
  •  Garthe I, Raastad T, Refsnes PE, Koivisto A, Sundgot-Borgen J. Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. Int J Sport Nutr Exerc Metab. 2011;21(2):97-104. 
  • Kerksick CM, Rasmussen CJ, Lancaster SL, Magu B, Smith P, Melton C, Greenwood M, Almada AL, Earnest CP, Kreider RB. J Strength Cond Res. 2006; 20 (3): 643-653.
  • Maestu J, Eliarim A, Jurimae J, Valter I, Jurimae T. Anabolic and Catabolic Hormones and Energy Balance of the Male Bodybuilders During the Preparation for the Competition. J Strength Condition Res. 2010; 24 (4): 1,074-1,081.
  • Mettler S, Mitchell N, Tipton KD. Increased protein intake reduces lean body mass loss during weight loss in athletes. Med Sci Sports Exerc. 2010; 42 (2): 326-337.