Prediction Model of Body Mass Index in Adolescents in the Era of COVID-19 Using Decision Tree Analysis: Body Mass Index of Adolescents

This study built a prediction model for BMI by sex of middle and high school students in the COVID-19 era by using 2021 Korea Youth Risk Behavior Survey. This study used data from 30,015 middle school and 24,833 high school students. The data was analyzed by using decision tree analysis. For male middle school students, if they did not engage in strenuous physical activity and spent more than 11 hours on a smartphone during the weekend, the obesity rate was the highest at 37.4%. Male high school students, those who did 0-1time strenuous physical activity a week and had medium-low level academic performance showed the highest level of obesity(36.2%). Middle school girls, when the academic performance was low and the anxiety disorder level was severe or conversely, the obesity rate was the highest at 18.4%. High school girls, the obesity rate was the highest at 20.5% when there was a significant change in the economic situation due to COVID-19 and the time spent on smartphone over the weekend was 9.8 hours or more. It is needed to develop a customized management and counseling program for obese adolescents.