High general self-efficacy is associated with less weight loss under a supervised dietary modification program

Self-efficacy is an important prospective predictor for behavior modification. As for weight loss intervention, many studies have shown significant associations between situation-specific self-efficacy and weight loss. In this study, we investigated the association between general self-efficacy and body weight change during a 14-week supervised dietary modification program. In total, 154 obese, middle-aged, Japanese women were selected as the subjects. The intervention program mainly comprised diet counseling. The diet counseling consisted of weekly lectures on weight loss practices and individual counseling by skilled dieticians. All subjects were instructed to choose and consume a well-balanced, 1200 kcal diet per day while also keeping a daily food diary in which they recorded in detail every food they ate during the intervention period. Body weight, waist circumference, and coronary heart disease risk factors were measured before and after the intervention. Energy intake and activity energy expenditure were assessed before and during the intervention. General self-efficacy was assessed with the General Self-Efficacy Scale (GSES) before the intervention. Body weight decreased significantly (-7.8 ± 2.7 kg; -11.4 ± 3.7%) following the intervention. The weight reduction was significantly greater for the low GSES group than for the other GSES groups. Self-efficacy regarding "degree of confidence in one's ability relative to others" especially influenced the association between the weight loss and the GSES score. Subjects' fat intake influenced the weight loss differences among GSES groups. In conclusion, inconsistent with previous studies, high general self-efficacy was associated with less weight loss under a supervised dietary modification program among middle-aged, Japanese women.