Binge status as a predictor of weight loss treatment outcome.

Abstract

A widely held clinical belief is that individuals with binge eating problems fare poorly in weight loss programs. The empirical evidence regarding the prognostic significance of binge eating, however, is mixed. The goals of this study were to examine psychological and behavioral characteristics associated with binge eating and the prognostic significance of binge eating for short- and long-term weight loss in a large sample of women treated for obesity. The dataset used in the current study was a combined sample of women (n = 444) who participated in one of three behavioral weight loss research studies. Measures of dieting and weight history were obtained at baseline. Body weight, the Binge Eating Scale (BES), a measure of perceived barriers to weight loss, the Beck Depression Inventory, the Block Food Frequency Questionnaire, and the Paffenbarger Physical Activity Questionnaire were assessed at baseline, 6 months and 18 months. Regression analyses examined cross-sectional associations between the BES and the other variables at baseline, prospective associations between baseline BES and changes in weight and the psychological and behavioral variables over time, and temporal covariations between BES and the other variables over time. Cross-sectional analyses showed baseline binge eating status to be strongly associated with dieting history, weight cycling, depressive symptomatology and perceived barriers to weight loss. Women with binge eating problems were also more likely to drop out of treatment. Baseline binge status was not associated with 6-month weight loss, but was weakly predictive of less weight loss success at 18 months. Binge status at baseline did not predict changes in dietary intake, physical activity, perceived barriers to weight loss or depressive symptomatology at either 6 months or 18 months. In time-dependent covariance analyses, changes in BES scores were significantly associated with changes in body weight, independent of changes in dietary intake and physical activity. However, when depression scores are included in the analysis, the association between binge score and body weight was no longer statistically significant. These findings suggest that baseline binge status was a weak prognostic indicator of success in women who are moderately obese and are seeking treatment for weight loss. Although assessments of binge status covary with weight loss and regain, the relationship appears to be mediated by psychological dysphoria.