Is Fat or Muscle Better for Bone Density?

According to research from the The Journal of Clinical Endocrinology & Metabolism (2014; doi.org/10.1210/jc.2013-3190), body weight is associated with bone strength. But in this regard, which component of body weight is more important—lean mass or fat mass?

Researchers from Sydney and from Ho Chi Minh City, Vietnam, wanted to learn whether bone mineral density differed among people with more fat mass versus more muscle tissue. The scientists looked at 44 studies that examined muscle, fat and BMD between 1989 and 2013. The studies included 4,966 men and 15,260 women aged 18-92.

“We extracted the correlations between lean mass, fat mass, and BMD at the lumbar spine, femoral neck, and whole body,” the authors reported. “The synthesis of correlation coefficients was done by the random-effects meta-analysis model.”

Lean mass proved to be three times more effective than fat mass at building bone density. The researchers noted that that the disparity was more prominent in men than in women. They also learned that “in postmenopausal women, the effects of lean mass and fat mass on BMD were comparable.”

“Lean mass exerts a greater effect on BMD than fat mass in men and women combined,” the authors concluded. “This finding underlines the concept that physical activity is an important component in the prevention of bone loss and osteoporosis in the population.”

PHOTOGRAPHY: Gyro2