A service evaluation of more than 1 million self-funding adults attending a community weight management programme.

Scaled interventions are required to address levels of overweight and obesity and reduce health inequalities. Little data is available on the effectiveness of community weight management programmes for participants self-selecting to attend across different socio-economic backgrounds. This analysis investigates 3, 6, and 12-month outcomes of adults joining a real-life community weight management programme. Weight, attendance and Indices of Multiple Deprivation (IMD) data from all fee-paying adults joining Slimming World in 2016 were collated. Data were analysed using descriptive and inferential statistics to determine predictors of weight loss. Mean BMI of 1 094 676 adults (7.6% male) was 33.0 ± 6.4 kg/m 2 . Mean % weight change at 3, 6, and 12 months was -5.0% ± 3.6%, -5.9% ± 5.2%, and -6.0% ± 5.8%. Those attending 75% sessions achieved greater weight loss with mean weight losses at 3, 6, and 12-months of 7.7% ± 3.3%, 11.3% ± 5.2%, and 14.1% ± 7.5%, respectively. Effect sizes from comparison of weight change between deprivation deciles were negligible, with similar outcomes in the most and least deprived deciles at 12-months (-5.7% ± 5.9% vs. -6.2% ± 5.9%). This service evaluation of more than 1 million adults attending a community weight management programme found they were able to achieve and/or maintain an average 6% weight loss at 12 months, with high attenders achieving >14% loss. Men and those with higher levels of deprivation were accessing the support and achieving significant weight losses. Slimming World as a real-life, scalable weight management programme is well placed to help adults manage their weight and address health inequalities.