Regional differences in obesity risk, sedentary behavior, and dietary patterns among university students in Saudi...

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/m²). 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.