Minimal Data to Support BCAA During Caloric Restriction


http://jissn.biomedcentral.com/artic...970-016-0128-9


The study reports a statistically significant change in fat mass for the group supplementing with BCAAs, but not in the placebo (isocalorically matched carbohydrate [CHO] beverage) group. However, this outcome is paradoxical with the results. Table 2 states that the BCAA group lost 0.6 kg of fat mass while the CHO group lost 1.4 kg.


The resting metabolic rate (RMR) dropped significantly in the BCAA group (412 kcal/day) but not in the CHO group (no data presented).


” Given the maintenance of lean body mass and the loss of fat mass in the BCAA group, and the loss of lean body mass and the apparent loss of fat mass in the CHO group, the RMR should have decreased in the CHO group but not the BCAA group


As noted in a recent review by Morton et al. [5], there is a paucity of evidence supporting a beneficial effect for BCAA supplementation in promoting increases in muscle protein synthesis or lean mass, and in fact there might be a detrimental impact given that the AAs appear to antagonize each other in terms of transport both into circulation and likely into the muscle.


As noted in our acknowledgements, performing heavy resistance exercise while following a strict hypocaloric diet is difficult, to say the least. Thus, there is a paucity of peer-reviewed work looking at reduced caloric intake, amino acid supplementation, body composition and muscle performance.