Regional differences in obesity risk, sedentary behavior, and dietary patterns among university students in Saudi Arabia: a multi-region cross-sectional study

Abstract

Overweight and obesity are rising among Saudi university students. Guided by Popkin’s nutrition transition theory, this study examined regional variation in overweight/obesity, sedentary behavior, and nutrition-transition dietary patterns. This cross-sectional study (March–May 2023) recruited 564 students from four Saudi administrative regions using a multistage sampling approach. Three colleges per university were selected across three academic domains; within each college, one male and one female class per academic level were invited; all eligible students completed the questionnaire. Students with prior type 2 diabetes were excluded. BMI was calculated from self-reported weight and height (overweight/obesity: ≥ 25.0 kg/m 2 ). Dietary patterns were identified using principal-component analysis of 17 food groups from a validated 66-item food frequency questionnaire. Physical activity was assessed via IPAQ-SF (sufficient: ≥ 150 min/week); composite sedentary behavior exposure was classified as low (< 8 h/day), moderate (8–12 h/day), or high (> 12 h/day). Logistic regression adjusted for sex, age, income, college type, region, and smoking. Overweight/obesity prevalence was 17.9% ( n  = 100/558); as BMI relied on self-reported anthropometrics, this is a conservative lower bound. A marked regional gradient was observed: 27.8% of Riyadh students were overweight/obese versus 8.8% in Makkah ( χ 2  = 25.48, p  < 0.001). Region showed the strongest association with overweight/obesity after adjustment: Riyadh (aOR = 4.62, 95% CI 2.23–9.59, p < 0.001) and male sex (aOR = 1.96, 95% CI 1.04–3.71, p  = 0.037) were the only significant predictors. Composite sedentary behavior exposure was high: 82.3% were moderately or highly sedentary (≥ 8 h/day), dominated by mobile phone use (3.75 h/day) and academic study (3.35 h/day). Sedentary behavior was higher in overweight/obese students (15.5 vs. 13.9 h/day; p  = 0.043). Nutrition-transition dietary patterns were not associated with overweight/obesity (aOR = 0.93, p  = 0.543). Region showed the strongest association with overweight/obesity, with Riyadh students at four-fold higher risk than Makkah students, suggesting that regional structural and environmental factors may contribute to obesity risk in this population. Prolonged mobile phone use and screen-based sedentarism were prevalent and associated with overweight/obesity. Campus interventions targeting sedentary screen behavior and regional food environments, particularly in Riyadh, are warranted; future studies should employ direct anthropometry to obtain unbiased prevalence estimates.