Social Determinants of Health Associated With Unhealthy Weight Management Behaviors Among Emerging Adult Women: Nationwide Cross-Sectional Study

Background Unhealthy weight management behaviors (UWMBs) have become increasingly common among emerging adult women, yet prior research has largely focused on psychological or perceptual correlates in isolation. In appearance-oriented contexts, structural influences, including social norms, may co-occur with individual characteristics to shape these behaviors. The social determinants of health (SDOH) framework offers a useful lens for examining UWMBs by jointly considering structural and intermediary determinants. Objective This study aimed to identify key SDOH associated with engagement in UWMBs among emerging adult women in South Korea by examining structural and intermediary determinants within a single adjusted model. Methods A nationwide cross-sectional survey was conducted among women aged 19 to 25 years using stratified sampling with quota allocation based on residential area and employment status. The final analytic sample included 1594 participants. UWMBs were assessed using a 9-item checklist; reporting at least 1 behavior in the past year was classified as UWMB engagement. Structural determinants included social norms, social influence, and socioeconomic position. Intermediary determinants included perceived body shape, body weight misperception, weight disparity, weight self-stigma, media health literacy, social network support, and BMI. Multivariable logistic regression analyses were performed to identify factors associated with UWMBs. Results Overall, 88% (1404/1594) of participants reported at least 1 UWMB in the past year, and 71.4% (n=1002) engaged in 2 or more UWMBs. Compared with women without UWMBs, those engaging in UWMBs reported stronger weight-related social norms, greater social influence, more distorted perceptions of body image, higher weight self-stigma, and greater media health literacy and social network support. In the multivariable model, UWMB engagement was significantly associated with perceived body shape (average vs thin: OR 2.41, 95% CI 1.52-3.83; P <.001; obese vs thin: OR 2.33, 95% CI 1.13-4.79; P =.02), descriptive norms (OR 1.38, 95% CI 1.19-1.61; P <.001), thin-ideal internalization (OR 1.32, 95% CI 1.01-1.71; P =.04), BMI (OR 1.10, 95% CI 1.01-1.19; P =.04), and educational attainment (in college vs high school or less; OR 1.69, 95% CI 1.09-2.62; P =.02; college or higher vs high school or less; OR 1.81, 95% CI 1.13-2.91; P =.01), with perceived body shape showing the largest odds ratios. Conclusions UWMBs are widely practiced among emerging adult women and are associated with both intermediary body image–related factors and broader sociocultural norms when considered simultaneously. These findings underscore the need for interventions that address appearance-related norms, particularly those disseminated through social media environments, rather than approaches focused solely on individual determinants. Future research should clarify the mechanisms linking structural and individual determinants to inform culturally relevant prevention strategies.