The association among bone, muscle, and fat mass was explored by Sowers et al. [37] in adult women. The authors categorized fat and lean tissue mass into tertiles, reporting a linear increase in mean femoral neck BMD for each tertile of muscle mass. Conversely, there was a nonlinear increase in BMD for each tertile of fat mass. BMD was similarly and equally greater in the high-muscle/low-fat and high-muscle/high-fat body composition types, suggesting that greater weight alone was not associated with increased BMD. Hence, if muscle does not grow in parallel with increased body weight, BMD is not optimized [37]. The authors concluded that low muscle mass was a risk factor for low BMD in young adult women, while higher fat mass was only protective when muscle mass was adequate.