Academic Major Differentially Influences Relationship Between Physical Activity And Disordered Eating Behaviors In Female Undergraduates

Prior research has examined independent associations between physical activity (PA) levels, body dissatisfaction, and academic major type with disordered eating behaviors in female undergraduates. However, a comprehensive understanding of the potentially synergistic relationship among these variables is lacking. PURPOSE: To examine whether disordered eating varies as a function of academic major (health- vs non-health-related), PA (total MET-min/week), body dissatisfaction, and body mass index (BMI; kg/m2) in female undergraduates. METHODS: Electronic surveys were distributed to approximately 28,000 undergraduates to assess demographic information (e.g., sex, age, race, year in school, academic major) and the aforementioned health-related variables. Interactions between academic major, PA, and body dissatisfaction on severity of disordered eating behaviors were examined with a linear mixed effects model that controlled for BMI and year in school, with random effects by subject. RESULTS: The sample consisted of 116 participants (59% health-related majors, 65% upperclassmen, M ± SD age = 20 ± 2 y, BMI = 23.35 ± 4.84, 91% white). Health-related majors reported greater PA, on average, compared to non-health-related majors (3303.16 ± 1545.05 vs 2778.39 ± 1788.58 total MET-min/wk; Cohen’s d = 0.31). The primary model revealed a significant main effect for body dissatisfaction (β = 0.84, 95%CI = 0.73 to 0.95) and a significant academic major x PA interaction (β = -0.16, 95%CI = -0.30 to -0.02). Analysis of simple effects indicated that body dissatisfaction (β = 0.84, 95%CI = 0.73 to 0.95) and PA (β = 0.14, 95%CI = 0.04 to -0.25) were positively associated with disordered eating in non-health-related majors, whereas only body dissatisfaction (β = 0.94, 95%CI = 0.84 to 1.04) was positively associated with disordered eating in health-related majors. CONCLUSIONS: Body dissatisfaction is a significant predictor of disordered eating among undergraduate students regardless of whether their academic major is health- or non-health-related. Future research should examine potential mechanisms to further our understanding of why academic major may differentially influence the relationship between PA and disordered eating in female undergraduates.