Prevalence and associated factors of normal-weight central obesity among community-dwelling adults 18 years and older in Mongolia

Background: This study investigated the prevalence of and factors associated with normal-weight central obesity (NWCO) among adults aged 18–64 years in Mongolia. Methods: Data were pooled from 5,287 participants aged 18–64 years who took part in repeated cross-sectional Mongolia STEPS surveys conducted in 2005, 2009, 2013, and 2019. Anthropometric and independent variables were measured using standard procedures. Factors associated with NWCO were examined using logistic regression analysis. Results: Among individuals with normal weight (BMI 18.5–24.9 kg/m²), the prevalence of NWCO across the four surveys was 34.0%, increasing from 8.7% in 2005 to 37.0% in 2019. Adjusted logistic regression analyses showed that, compared with 2005, survey year 2019 (AOR = 3.07, 95% CI: 2.29–4.12), middle age (45–64 years) (AOR = 2.14, 95% CI: 1.65–2.79), low physical activity (AOR = 1.31, 95% CI: 1.05–1.64), and hypertension (AOR = 1.44, 95% CI: 1.09–1.90) were positively associated with NWCO. In contrast, male sex (AOR = 0.06, 95% CI: 0.01–0.27) and higher education (AOR = 0.68, 95% CI: 0.52–0.85) were negatively associated with NWCO. Conclusions: Approximately one in three normal-weight adults in Mongolia had central obesity. To prevent NWCO, healthcare providers should emphasize the importance of maintaining a healthy lifestyle, including adequate physical activity and other weight-related behavioural changes.