Alcohol and Binge Eating as Mediators Between Posttraumatic Stress Disorder Symptom Severity and Body Mass Index

Objective: Sexual-minority women are at elevated risk for obesity, as well as exposure to traumatic events. Rates of obesity are elevated in individuals with posttraumatic stress disorder (PTSD), but little is known about why this relationship exists. Behavioral mechanisms, such as eating patterns and alcohol use, are possible explanations that would be clinically useful to identify. Methods: Binge eating and alcohol use were longitudinally investigated as mediators of the relationship between PTSD symptom severity and body mass index (BMI) in a large sample of young-adult, sexual-minority women (N = 425). PTSD symptom severity was assessed at baseline, binge eating and alcohol use were assessed 12 months later, and BMI was assessed 24 months after baseline. Results: Using a multiple mediator model, higher baseline PTSD symptom severity was found to be significantly associated with higher BMI 2 years later, operating through binge-eating behavior but not through alcohol use. Exploratory moderator analyses found that this effect was higher for those with lower baseline BMI. Conclusions: Results suggest that higher PTSD symptoms are longitudinally associated with increased BMI and that binge eating behavior is one factor that explains this relationship.