The relationship of internalized weight bias to weight change in treatment-seeking overweight adults

Ph.D. University of Hawaii at Manoa 2011.Includes bibliographical references.Objective: The present study was designed to explore whether behavioral weight loss treatment is associated with changes in internalized weight bias among overweight and obese men and women. The relationship of internalized weight bias to treatment outcome was assessed, as well as its relationship to other psychological variables associated with weight change, including body image concern, self-esteem, anti-fat attitudes, depressive symptoms, anxiety and stress. Method: Participants were 106 overweight and obese men and women enrolled in a treatment outcome study using the Lifestyle Balance Program, a behavioral weight loss program emphasizing dietary change and increasing physical activity. Eligible participants were randomly assigned by treatment site to either a standard care condition following the Lifestyle Balance Program, or to a continuing care condition which included all elements of the Lifestyle Balance Program, plus 18 additional months of participant-led self-help. Participants completed measures of internalized weight bias, anti-fat attitudes, self-esteem, body image concern, depressive symptoms, anxiety and stress at the start of treatment, following completion of active treatment, and again at six-months post-treatment (i.e. follow-up). Results: Participants who completed treatment lost, on average, 5.22% of initial body weight at post-treatment with an additional loss of 0.50% of initial body weight from post-treatment to follow-up, with no significant differences between treatment conditions on measures of weight change and psychological functioning. Weight bias internalization was shown to significantly decrease over the course of treatment and again at follow-up and was associated with percent change in initial body weight from baseline to six-month follow-up. Participants reporting low levels of internalized weight bias at baseline lost twice as much weight when compared to participants reporting high levels of internalized weight bias at baseline. Though significant correlations were found between percent change in initial body weight and measures of internalized weight bias, body image concern and self-esteem, regression models failed to identify significant predictors of weight change among the study variables. Internalized weight bias was additionally shown to be related to body image concern, anti-fat attitudes, depression and self-esteem. Baseline scores of internalized weight bias contributed to the prediction of change in body image scores from baseline to follow-up and from post-treatment to follow-up. Discussion: Findings from the present study indicate a relationship between internalized weight bias and weight change in the context of behavioral weight loss treatment. Elements of behavioral weight loss treatment, such as cognitive restructuring, may contribute to the reduction of bias demonstrated in the present study. Study results also indicate the importance of assessing baseline levels of internalized weight bias, as having higher levels of internalized weight bias was associated with poorer weight loss outcomes. Limitations of the present study are discussed, including methodological issues such as the use of self-report questionnaires and the clinical significance of the findings. Future research may design interventions to specifically target internalized weight bias, through such methods as cognitive restructuring or cognitive defusion techniques, particularly among those individuals evidencing greater internalized weight bias