title: Weight outcomes audit in 1.3 million adults during their first 3 months' attendance in a commercial weight management programme.
abstract: BACKGROUND
  Over sixty percent of adults in the UK are now overweight/obese. Weight management on a national scale requires behavioural and lifestyle solutions that are accessible to large numbers of people. Evidence suggests commercial weight management programmes help people manage their weight but there is little research examining those that pay to attend such programmes rather than being referred by primary care. The objective of this analysis was to evaluate the effectiveness of a UK commercial weight management programme in self-referred, fee-paying participants.
  
  
  METHODS
  Electronic weekly weight records were collated for self-referred, fee-paying participants of Slimming World groups joining between January 2010 and April 2012. This analysis reports weight outcomes in 1,356,105 adult, non-pregnant participants during their first 3 months' attendance. Data were analysed by regression, ANOVA and for binomial outcomes, chi-squared tests using the R statistical program.
  
  
  RESULTS
  Mean (SD) age was 42.3 (13.6) years, height 1.65 m (0.08) and start weight was 88.4 kg (18.8). Mean start BMI was 32.6 kg/m(2) (6.3 kg/m(2)) and 5 % of participants were men. Mean weight change of all participants was -3.9 kg (3.6), percent weight change -4.4 (3.8), and BMI change was -1.4 kg/m(2) (1.3). Mean attendance was 7.8 (4.3) sessions in their first 3 months. For participants attending at least 75 % of possible weekly sessions (n = 478,772), mean BMI change was -2.5 kg/m(2) (1.3), weight change -6.8 kg (3.7) and percent weight change -7.5 % (3.5). Weight loss was greater in men than women absolutely (-6.5 (5.3) kg vs -3.8 (3.4) kg) and as a percentage (5.7 % (4.4) vs 4.3 % (3.7)), respectively. All comparisons were significant (p < 0.001). Level of attendance and percent weight loss in the first week of attendance together accounted for 55 % of the variability in weight lost during the study period.
  
  
  CONCLUSIONS
  A large-scale commercial lifestyle-based weight management programme had a significant impact on weight loss outcomes over 3 months. Higher levels of attendance led to levels of weight loss known to be associated with significant clinical benefits, which on this scale may have an impact on public health.
authors.affiliation: Nutrition and Research Department, Slimming World, Clover Nook Road, Somercotes, Alfreton, Derbyshire, DE55 4RF, UK. james.stubbs@slimming-world.com.|College of Life and Natural Sciences, University of Derby, Kedleston Road, Derby, DE22 1GB, UK. james.stubbs@slimming-world.com.
authors.forename: R James
authors.initials: RJ
authors.lastname: Stubbs
authors.affiliation: Nutrition and Research Department, Slimming World, Clover Nook Road, Somercotes, Alfreton, Derbyshire, DE55 4RF, UK. liam.morris@slimming-world.com.
authors.forename: Liam
authors.initials: L
authors.lastname: Morris
authors.affiliation: Nutrition and Research Department, Slimming World, Clover Nook Road, Somercotes, Alfreton, Derbyshire, DE55 4RF, UK. carolyn.pallister@slimming-world.com.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Pallister
authors.affiliation: Biomathematics and Statistics Scotland, The Rowett Institute of Nutrition and Health, Greenburn road, Aberdeen, AB21 9SB, UK. g.horgan@abdn.ac.uk.
authors.forename: Graham
authors.initials: G
authors.lastname: Horgan
authors.affiliation: Nutrition and Research Department, Slimming World, Clover Nook Road, Somercotes, Alfreton, Derbyshire, DE55 4RF, UK. jacquie.lavin@slimming-world.com.
authors.forename: Jacquie H
authors.initials: JH
authors.lastname: Lavin
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001835:Body Weight; D003132:Commerce; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000628:therapy*; D050177:Overweight / Q000628:therapy; D011320:Primary Health Care; D015397:Program Evaluation; D012737:Sex Factors; D006113:United Kingdom; D015431:Weight Loss; D061217:Weight Reduction Programs