Supplements promoted to assist with physique changes: gain in lean mass and loss of body fat mass
| Supplement | Proposed mechanism of action | Evidence for efficacy25 |
| Gaining LBM* | ||
| Protein Usually comprised isolated proteins from various sources (whey and soy most common) Recommended daily dose: 1.6 g protein/kg/day optimal (up to 2.2 g/kg/day with no adverse effects) Recommended per-meal doses: 0.3–0.5 g protein/kg (3–4 times per day and in close temporal proximity to exercise, with postexercise being consistently shown to be effective) | Enhances lean mass gains when ingested during programmes of resistance training due to increased provision of building blocks (amino acids) and leucine as a trigger for a rise in muscle protein synthesis and suppression of muscle protein breakdown | Meta-analyses focusing on younger and older participants have shown positive effects enhancing gains in muscle mass,161 162 but effects are not large. |
| Leucine | Stimulates muscle protein synthesis and suppresses protein breakdown (possibly through insulin) | Short-term mechanistic data available,137 but no long-term trials showing efficacy163 |