Lifestyle and psychosocial factors associated with maintenance of normal body mass index in college students: a cross sectional study.

Objectives: The purpose of this study was to identify lifestyle and psychosocial factors associated with maintenance of normal body mass index (BMI, 18.5-24.9 kg/m). Undergraduate students (n = 2781; 7.1% response rate) at a Big Ten university responded to a survey in 2018. BMI was calculated from the reported weight and height at the time of the survey and upon entering the university. Logistic regression analyses examined lifestyle and psychosocial health factors associated with maintenance of normal BMI by academic year.

Results: Current BMI was within normal range for 68.8% of freshmen and 60.6% of seniors. Never consuming fast food was a significant predictor for maintaining normal BMI in sophomores (OR 3.78; 95% CI 1.61, 8.88; p < 0.01) and juniors (OR 7.82; 95% CI 2.14, 28.65; p < 0.01). In seniors, better psychosocial health (OR 1.40; 95% CI 1.12, 1.76; p < 0.01) was the only significant predictor for maintaining one's normal freshman BMI category. Among those within the normal BMI range upon entering the university, psychosocial health (OR 1.31; 95% CI 1.10, 1.55; p < 0.01) was the only predictor of retaining one's absolute BMI within ± 3% as a senior. Prospective studies are needed to better understand the interaction between environment, behavior, and psychological health involved in retaining normal weight.