The Effects of Weight Loss on Relative Bone Mineral Density in Premenopausal Women

Objective: This study compared BMD relative to body weight following a similar to 6-month weight loss program and a 1-year weight maintenance phase in premenopausal women and determined whether African American (AA) and European-American (EA) women's BMD respond similarly during weight loss. Design and Methods: Premenopausal women (n = 115, 34 +/- 5 years) were evaluated in an overweight state (BMI between 27 and 30 kg/m(2)), following an 800 kcal/day diet/exercise program designed to reduce BMI<25 kg/m(2), and 1-year following weight loss. Results: BMD relative to body weight (Z-scores) increased after weight loss, but decreased during the 1-year weight maintenance phase. All 1-year follow-up BMD Z-scores were increased (except L1) compared to baseline measurements (P < 0.05). These sites included the hip neck (+0.088, P = 0.014), total hip (+0.099, P = 0.001), L2 (+0.127, P = 0.013), L3 (+0.135, P = 0.014), and L4 (+0.199, P = 0.002). AAs had significantly higher absolute BMD at all sites (P < 0.05) compared to EAs, but no time by race interactions were evident during weight loss (except in L3). Conclusion: These results may indicate that weight loss is safe with regard to bone health for overweight premenopausal women.