Associations between dietary patterns,lifestyle factors,and body mass index among female nutrition students: A classification and regression tree analysis

Background: The university period is critical for establishing positive lifestyle habits that can reduce long-term risk for chronic diseases. Aim: To analyze the associations between dietary patterns, lifestyle factors, and body mass index (BMI) among female university students enrolled in the Nutrition and Dietetics program at the University of Antioquia. Methods: A cross-sectional analysis was conducted with 251 female students (22.0 ± 2.8 years) selected via proportion-based random sampling. Sociodemographic, anthropometric, lifestyle, and food frequency data were collected using standardized questionnaires administered by trained nutritionists. A Dietary Index (DI) was calculated from 35 food groups to assess diet quality. Kendall's Tau-C test was used to evaluate associations between specific food groups and BMI. Additionally, Classification and Regression Tree (CART) analysis was applied to identify the variables most strongly associated with BMI, modeled both as categorical and continuous outcomes. Results: Students with higher food spending (p = 0.013), a healthy DI (p = 0.015), and enrollment in the contributory health system (p = 0.027) were more likely to have a normal BMI. CART analysis revealed that better DI scores and reduced screen time were associated with lower BMI, with the DI emerging as the primary discriminating variable. Individual food group analysis showed significant associations between BMI and frequent consumption of high-sodium sauces (p = 0.005; r = 0.142), canned foods (p = 0.034; r = −0.111), and sugar-sweetened beverages (p = 0.003; r = −0.113), though these correlations were weak. Conclusion: University settings should prioritize interventions such as healthy food services, nutrition education workshops, and accessible recreational facilities to promote healthy lifestyles among students. These strategies may help reduce the risk of overweight and obesity and support long-term health.