RESUMEN
OBJECTIVE: To assess the effect of a 3 month behaviour modification weight management programme on self-efficacy and anthropometric variables among obese women seeking treatment at an obesity management clinic and to compare self-efficacy among these obese women to non-obese women. DESIGN: Cross sectional. SUBJECTS: A total of 161 non-obese (BMI 22.6+/-2.9 kg/m(2)) and 138 obese (BMI 37.7+/-5.8 kg/m(2)) women of similar age. MEASUREMENTS: Self-efficacy in relation to eating was assessed by the Weight Efficacy Lifestyle (WEL) questionnaire. Demographic information was obtained by interview and questionnaire in the obese and by questionnaire in the non-obese. Anthropometric measurements were obtained by direct measure in the obese and BMI was calculated from self-reported weight and height in the non-obese. RESULTS: At entry to the programme obese women scored significantly less (P<0.0001) than non-obese women on the WEL (99.4+/-34.1 vs 139.0+/-24.9). Women who completed the programme (n=65) demonstrated a decrease in waist circumference of 3.9+/-5.3 cm, a 10.0+/-11.5% loss of excess weight and a significant improvement in total WEL score from 106.0+/-30.3 to 126.5+/-28.4. CONCLUSION: Improvements in some dimensions of self-efficacy among obese women were of sufficient magnitude to attain scores similar to women of a normal weight. The WEL questionnaire may provide an additional measure of success as well as provide positive feedback and encouragement to the client.