Abstract
BACKGROUND: It is not clear if behaviour change programmes are more or less effective for weight management in people with high BMIs than for those who are moderately overweight. An earlier service evaluation reported on the rate and extent of weight loss in a primary care/commercial weight management organisation partnership scheme, in 34,271 patients were referred by their health care professionals to a UK commercial weight management organisation, Slimming World for 12 weekly sessions. This project updated that service evaluation by examining weight loss outcomes as a function of initial BMI in the same 34,271 patients. FINDINGS: Patients referred to the scheme (n = 34,271) were categorised by BMI groups <30 kg/m(2), 30-34.9 kg/m(2), 35-39.9 kg/m(2) and to ≥ 40 kg/m(2). Mean weight losses after 12 weekly sessions were 2.9, 3.6, 4.1, and 4.8 kg for each BMI category respectively. Regression analysis showed that after adjusting for age and gender, relative to the <30 kg/m(2) group, absolute weight losses were 0.8, 1.4 and 2.4 kg more for the 30-34.9 kg/m(2), 35-39.9 kg/m(2) and to ≥ 40 kg/m(2) groups, respectively (all p<0.001). Percent weight loss was similar in each BMI category: 3.7%, 4.0%, 4.0% and 3.9%, respectively (p<0.001). CONCLUSIONS: This service evaluation demonstrates that 12 week referral to a commercial organisation is as effective for people with high BMIs as for those who are moderately overweight.