We previously found that impulsivity (delay discounting), night-eating, and food addiction symptoms were related to psychopathology preoperatively and now examine these variables as predictors of weight loss at 6 and 12 months postoperatively.
Patients completed assessments of psychosocial functioning and impulsivity preoperatively and 6- and 12-months postoperatively, including the Structured Clinical Interview for DSM-5, Eating Disorder Examination, Eating Inventory (EI) and computer-based impulsivity tasks. General linear models using these measures as predictors, controlling for age, race, sex, BMI, and surgery type, were used to examine percent weight change at 6- and 12-months.
Participants were 40.1+11.0 years old with a BMI=45.9+6.2 kg/m2; 87% female, 61.5% black, 29.9% white, 8.6% other. Most (87%) underwent vertical sleeve gastrectomy; 13% received the Roux-en-Y gastric bypass. At 6 and 12 months, participants lost 22.97+-5.11% and 26.18+-7.6% of their weight, respectively. Presence of a current or lifetime psychiatric diagnosis or impulsivity at baseline did not predict weight loss at 6 or 12 months. More days with subjective binge episodes (p<0.0001) at baseline predicted greater weight loss at 6 months. Higher levels of Disinhibition (EI) (p=0.0133) and Hunger (EI) (p=0.0107) at baseline predicted greater weight loss at 12 months.
Among this racially diverse sample, psychopathology and impulsivity were unrelated to early weight loss. However, symptoms of disordered eating preoperatively predicted greater weight loss in the first postoperative year, perhaps suggesting that the surgery may reduce the impact of these eating behaviors in the early months after surgery.