An interim analysis of the influence of eating disorder risk, body dissatisfaction, physical activity, and diet on bone mineral density in college-aged females

Background This study aimed to examine relationships between BMD z-scores, eating disorder (ED) risk, body image dissatisfaction (BID), physical activity, and dietary intake in college females.Methods College-aged females (n = 20, age: 19 ± 1 yrs, weight: 58 ± 9 kg, BF%: 29 ± 6%) participated in this cross-sectional study. Whole body, total hip, femoral neck, and lumbar spine BMD were assessed using dual-energy x-ray absorptiometry. Participants completed validated questionnaires to assess ED risk and BID. Objective physical activity (daily steps, daily physical activity energy expenditure (PAEE), time spent in sedentary (PAs), light (PAL), moderate (PAM), and vigorous (PAV) zones), and dietary intake were quantified across 3-days via a wrist-worn accelerometer and a self-reported food log, respectively. Spearman correlations evaluated relationships between BMD, ED scores, BID, physical activity metrics, and dietary intake (p < 0.05).Results 47–65% of participants had low BMD (z-score < 0) at whole-body, hip, and spine sites, with 40% classified as osteopenic (Ta ble 1). Additionally, 20% were at risk of ED and 65% conveyed BID. Participants averaged 15,789 ± 4,116 daily steps, expending 986 ± 396 active calories. Total hip BMD z-scores were positively associated with daily steps (r = 0.462, p = 0.046), PAEE (r = 0.493, p = 0.032), and PAM (r = 0.575, p = 0.010). No other relationships were observed between BMD, ED risk, BID, and dietary intake (calories, carbohydrates, protein, fat, calcium) (p > 0.05).Conclusions A high incidence of low BMD was observed across all sites (whole body, total hip, femoral neck, and lumbar), with BMD z-scores associated with physical activity (daily step counts, PAEE, and PAM), but not with dietary intake, ED risk, or BID. These findings highlight the importance of physical activity for maintaining bone health in premenopausal females. As BMD reflects long-term bone health, it may not capture acute dietary or lifestyle changes, highlighting the need to assess dynamic bone turnover markers.