The Claim
Supplementation with beta-hydroxy-beta-methylbutyrate (HMB) at 3 grams per day for at least four weeks is associated with a small, nonsignificant increase in fat-free mass (effect size: 0.30 ± 0.13; 95% CI: −0.07 to 0.68; p = 0.08) in athletic populations, with potential benefit only when daily protein intake is below 1.6 g/kg of body weight.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Taking 3 grams of HMB daily for four weeks or longer may be linked to a very small increase in lean body mass in athletes, but this effect is not statistically significant and may only occur if protein intake is less than 1.6 grams per kilogram of body weight per day.
See the scientific wording
Supplementation with beta-hydroxy-beta-methylbutyrate (HMB) at 3 grams per day for at least four weeks is associated with a small, nonsignificant increase in fat-free mass (effect size: 0.30 ± 0.13; 95% CI: −0.07 to 0.68; p = 0.08) in athletic populations, with potential benefit only when daily protein intake is below 1.6 g/kg of body weight.
What the research says
1 studyStudy: Does HMB Enhance Body Composition in Athletes? A Systematic Review and Meta-analysis
This study found that taking HMB for a month or more might help athletes gain a tiny bit of muscle, but only if they’re not eating enough protein. The effect is small and not certain, but it doesn’t contradict what the claim says.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.