Weight control self-efficacy types and transitions affect weight-loss outcomes in obese women.

Matching obesity treatments to heterogeneous clients is a recent evolution in the development of more effective weight-control programs, yet most interventions emphasize the external features of treatments rather than the internal belief structures of individuals. The purpose of this study was to determine whether Q methodology would identify distinct types of weight-control self-efficacy beliefs in obese women that would be linked to outcomes of a weight-loss program. Fifty-four women (45 +/- 9 yrs, Mean +/- SD) 136 +/- 10% over ideal body weight participated in a 9-month nutritional/behavioral weight loss program. Two major self-efficacy categories emerged through factor analysis of Q sorts: assureds and disbelievers. The assureds (n = 28) had the strongest self-efficacy beliefs and at baseline reported significantly (p < .01) greater self-esteem and less depression than the disbelievers (n = 26). By posttreatment, the assureds had lost significantly more weight (10 +/- 6 vs. 7 +/- 7 kg). Regrouping the data for analysis by posttreatment self-efficacy types demonstrated transitions in the self-efficacy beliefs of the women during treatment. Those who were disbelievers at baseline but became assureds posttreatment (n = 7) lost twice as much weight as the women who started and finished as disbelievers (n = 19) (10 +/- 7 kg vs. 5 +/- 5 kg). The posttreatment assureds (n = 32) lost significantly more weight than the disbelievers (n = 22) (10 +/- 6 vs. 6 +/- 5 kg), and reported better self esteem, mood, and eating patterns. Thus, assessment of intrinsic belief systems, particularly weight-control self-efficacy, may provide new directions for designing interventions that target distinctly different needs of obese women to affect greater weight loss and more positive affective states.