Objective.—To describe the prevalence of childhood overweight and obesity in rural high- and low-altitude populations of southwestern Saudi Arabia and to identify specific at-risk groups within these populations.

Methods.—A cross-sectional study was conducted on 912 school children and adolescents aged 6–15 years born and living permanently at high altitudes (2800–3150 m) and 972 children and adolescents of comparable ages born and living permanently at low altitudes (≤500 m). Height and weight were measured. For children <10 years, the weight-to-height index according to World Health Organization (WHO) standards was used for assessing overweight and obesity. For adolescents 10–15 years, overweight and obesity were assessed by age and gender-specific percentiles for body mass index based on the WHO/National Centre for Health Statistics reference population. A questionnaire was used for measuring parents' socioeconomic status.

Results.—The overall prevalence of overweight and obesity at high and low altitudes was 10%. The study showed that some school children and adolescents were at a significantly higher risk of developing overweight and obesity. Significant risk factors included moderate-to-high parental income, age ≥10 years, high-altitude birth and residence, and female sex (crude odds ratio 3.2 [95% CI, 1.8– 5.5], 2.3 [95% CI, 1.6–3.2], 2.1 [95% CI, 1.5–2.9], and 1.9 [95% CI, 1.4–2.6], respectively). A multivariate analysis using the direct binary logistic regression model revealed that moderate-to-high parental income, age ≥10 years, female sex, and high-altitude birth and residence were significant independent predictors of childhood overweight and obesity. (adjusted OR 3.2 [95% CI, 1.6–2.6], 2.6 [95% CI, 1.8–3.8], 2.0 [95% CI, 1.6–2.9], and 1.8 [95% CI, 1.3–2.6]), respectively.

Conclusion.—The present study identified risk factors for childhood overweight and obesity in Saudi Arabia. Among these, high altitude was a significant and independent factor. Future research is warranted to evaluate the exact mechanism by which a high-altitude environment may contribute to childhood overweight and obesity.