Developing and Validating a Model for Predicting Child and Adolescent Obesity in Greater Beirut, Lebanon: A Population and School-Based Study

Objectives: The study aimed to identify predictors of child and adolescent obesity at the individual and school levels in Greater Beirut, Lebanon. Methods: This was a cross-sectional study using a representative sample of schoolchildren aged 8-12 years old residing in Greater Beirut, Lebanon (n=2,125). The study employed a two-stage sampling approach. The first stage randomly selected 50 schools stratified by type of school (public, private, and private free) from a list provided by the Ministry of Education in Lebanon. The second stage included randomly assigning 50 students from grades 4 to 6 from each school that participated in the study. Potential predictors of obesity at the individual and school levels were collected through a face-to-face survey during January to May 2022. The outcome was obesity, defined as a BMI Z-score > +2SD using the WHO growth standard. A LASSO logistic regression model was used to predict obesity. The model's discrimination was measured through the area under the receiver operating characteristic curve (C-Statistic). The model's calibration was measured through the calibration slope (C-Slope). Results: Almost 18% of the participants were obese. Individual-level obesity predictors included: being a male, being Lebanese compared to other nationalities, skipping breakfast on school days, and eating while watching television or other screen ≥ 3 days a week. Attending public school was the only school-level predictor retained. The model showed moderate discrimination of C-Statistic: 0.622 (95%CI:0.58-0.66) and had good calibration with a C-Slope of 1.04 (95%CI:0.70-1.38). Conclusions: The findings underline the ongoing need to address child and adolescent obesity in Greater Beirut by promoting healthy dietary habits focusing on breakfast consumption and limiting screen use during meals. It also emphasizes that community-level socioeconomic and structural factors play a role in schoolchildren's obesity in Lebanon, and that interventions are needed in public schools to address the threats to healthy eating among schoolchildren. Funding Sources: International Development Research Centre - Canada.