Objective
Interpersonal psychotherapy (IPT) prevents weight gain in adults with obesity and binge-eating-disorder, and is especially effective among those with increased psychosocial problems. However, IPT was not superior to health-education (HE) to prevent excess weight gain at 1-year follow-up in 113 adolescent girls at high-risk for excess weight gain because of loss-of-control (LOC)-eating and high BMI (kg/m2) (Tanofsky-Kraff et al., 2014).
Method
Participants from the original trial were re-contacted 3-years later for assessment. At baseline, adolescent- and parent-reported social-adjustment problems and trait-anxiety were evaluated. At baseline and follow-ups, BMIz and adiposity by dual-energy X-ray absorptiometry were obtained.
Results
Nearly 60% were re-assessed at 3-years, with no group differences in participation (psâ„.70). Consistent with 1-year, there was no main effect of group on change in BMIz/adiposity (psâ„.18). In exploratory analyses, baseline social-adjustment problems and trait-anxiety moderated outcome (ps<.01). Among girls with high self-reported baseline social-adjustment problems or anxiety, IPT, compared to HE, was associated with the steepest declines in BMIz (p<.001). For adiposity, girls with high- or low-anxiety in HE, and girls with low-anxiety in IPT experienced gains (psâ€.03), while girls in IPT with high-anxiety stabilized. Parent-reports yielded complementary findings.
Conclusion
In obesity-prone adolescent girls, IPT was not superior to HE in preventing excess weight gain at 3-years. Consistent with theory, exploratory analyses suggested that IPT was associated with improvements in BMIz over 3-years among youth with high social-adjustment problems or trait-anxiety. Future studies should test the efficacy of IPT for obesity prevention among at-risk girls with social-adjustment problems and/or anxiety.