<![CDATA[Purpose: This study aimed to analyze the dominant risk factors (school type, knowledge, attitude, and physical activity) associated with abnormal Body Mass Index (BMI) among high school students in East Kalimantan. Methods: This quantitative, cross-sectional study included 184 students from one boarding school (n=84) and one day high school (n=100) in East Kalimantan, selected using purposive sampling. We collected data on knowledge, attitude, and physical activity using structured questionnaires, and determined BMI through direct anthropometric measurements of height and weight. Data were analyzed using binary logistic regression to estimate odds ratios (OR) as risk indicators, with a 95% confidence level (α = 0.05). Results: The Hosmer and Lemeshow goodness-of-fit test showed that the logistic regression model fit the field data well (p = 0.689 > 0.05). Multivariable analysis showed that school type was the strongest risk factor for abnormal BMI among students (p = 0.009, OR = 2.262; 95% CI: 1.221–4.190). Students in non-boarding schools had a 2.262-fold higher risk of having an abnormal BMI compared to those in boarding schools. Knowledge, attitude, and physical activity variables showed no statistically significant effect (p >0.05). Conclusion: School type is the strongest predictor of BMI status among high school students in East Kalimantan. Interventions should focus on reducing disparities in institutional food and physical activity environments between boarding and day schools, while prospective longitudinal studies are needed to establish causality.]]>
