Association between body fat percentage and bone mineral density in adults: Data from NHANES 2011 to 2018

Osteoporosis is a major health problem that has far-reaching consequences for both individuals and society. There is a strong link between obesity and osteoporosis. Body fat percentage (%BF) is a more accurate measure of obesity than body mass index (BMI) because it directly reflects the amount of body fat and has been strongly associated with health risks. In this study, we aimed to explore the correlation between %BF and lumbar bone mineral density (BMD) in US adults aged 20 to 59 years. This cross-sectional study was based on data from the National Health and Nutrition Examination Survey conducted between 2011 and 2018. Weighted multivariable linear regression models, threshold effect analysis, smooth curve fitting, and subgroup evaluations were utilized to explore the association between %BF and lumbar BMD. This study included 10,363 participants. After adjusting for several variables, we observed a negative connection between %BF and lumbar BMD [-0.0063 (-0.0076, -0.0051)]. A threshold point was identified at %BF = 37.5, below which lumbar BMD decreased by 0.0053 g/cm2 per unit increase in %BF. Above this threshold, lumbar BMD decreased by 0.0097 g/cm2 per unit increase in %BF. Subgroup analysis suggested that gender, race, and BMI influenced the association between %BF and lumbar BMD (P < .05). Thus, maintaining a healthy %BF may prevent osteoporosis. Regular %BF assessments and necessary precautions are central to lower the possibility of osteoporosis.