Factors Associated with Overweight and Obesity and Their Prevalence Among Medical Students in the Eastern Province of Saudi Arabia: A Cross-Sectional Study

Background and Objectives: Overweight and obesity among medical students represent significant public health concerns as unhealthy weight status during medical training may affect future health and professional counseling practices. Understanding the factors associated with BMI categories may help inform future university-based health promotion strategies. This study aimed to assess the prevalence of overweight and obesity and examine sociodemographic, lifestyle, and dietary factors associated with BMI categories among medical students. Methods: This cross-sectional study was conducted among medical students at the College of Medicine, King Faisal University, between December 2025 and January 2026. Students were selected using proportionate stratified random sampling according to academic year and gender. Of the 422 students invited to participate, 382 students completed the study questionnaire and anthropometric assessment, yielding a response rate of 90.5%. Height and weight were measured in person using calibrated equipment. Data on demographic characteristics, lifestyle habits, dietary patterns, smoking, sleep, and physical activity were collected through a structured face-to-face questionnaire. Multinomial logistic regression analysis was performed to examine factors associated with BMI categories, using normal weight as the reference category. Results: A total of 382 medical students were included, with a median age of 21 years. The prevalence of overweight was 19.9%, and the prevalence of obesity was 14.1%, resulting in a combined overweight and obesity prevalence of 34.0%. In the adjusted multinomial logistic regression model, male gender was associated with being overweight compared with having normal weight (aRRR = 2.71, 95% CI: 1.22–5.98). Obesity showed associations with below-average financial status (aRRR = 13.53, 95% CI: 1.98–92.22), current smoking (aRRR = 17.00, 95% CI: 2.50–115.47), soft drink intake of 2–3 times/week (aRRR = 4.57, 95% CI: 1.13–18.49), and lower physical activity, including no activity (aRRR = 11.61, 95% CI: 2.07–65.01), rare activity (aRRR = 7.54, 95% CI: 2.21–25.80), and physical activity several times/month (aRRR = 5.86, 95% CI: 1.78–19.31). Always eating breakfast was associated with overweight (aRRR = 2.23, 95% CI: 1.05–4.73). Several adjusted estimates had wide confidence intervals, indicating limited precision. Conclusions: Overweight and obesity were common among medical students at King Faisal University and were associated with several sociodemographic, lifestyle, and dietary variables. Because of the cross-sectional design and the imprecision of some adjusted estimates, these findings should be interpreted as associations rather than causal relationships. Future longitudinal and multicenter studies using validated lifestyle measures are recommended to clarify temporal relationships and guide university-based health promotion strategies.