Weight Management and Body Composition Goals
Weight Management and Body Composition Goals
This domain covers energy balance, safe rates of weight loss, lean mass retention, and body composition goals. The exam emphasizes sustainable deficits and the risks of rapid weight cutting.
Core rules
- Energy deficit of about 300–500 kcal/day supports gradual fat loss; larger deficits increase lean mass loss and fatigue.
- Aim for 0.5–1.0% of body mass loss per week; faster loss is rarely sustainable.
- Protein during deficit: 1.6–2.4 g/kg/day helps preserve lean mass.
- Resistance training and adequate sleep support lean mass retention.
- Refeeds or diet breaks can help adherence and training quality; they do not negate energy balance.
- Avoid very low energy availability, which can cause RED-S, hormonal disruption, and bone stress injury.
Worked example
An 80 kg athlete at 20% body fat has fat mass 16 kg and fat-free mass 64 kg. Target 15% body fat: target weight = 64 ÷ 0.85 = 75.3 kg. Fat loss needed = 80 − 75.3 = 4.7 kg. At 0.5 kg/week, that is about 9–10 weeks. A 500 kcal/day deficit is a reasonable starting point. Reasoning: set the target from fat-free mass, then calculate rate and timeline; monitor performance and lean mass, not just weight.
Traps
Using crash diets before competition; cutting fat too low and impairing hormones; ignoring menstrual dysfunction or RED-S; and assuming scale weight alone reflects fat loss.