Statistical analysis
depression, weight loss, anxiety
SENSITIVITY
Summary statistics are presented as mean (SD) or median (IQR) for continuous variables, and as numbers and percentages for categorical variables. Percentage weight loss at 6 and 12 months was compared between the three treatment groups, using analysis of covariance (ANCOVA) with baseline weight included as a covariate. Additional adjustments were made for a priori baseline confounders; estimated lifetime BC risk, age, Townsend deprivation score, anxiety and depression scores. Adjusted means and 95% confidence intervals (CIs) are reported, along with global F-tests to compare differences between the groups, and post-hoc pairwise comparisons where appropriate. Multiple imputation was used for missing outcome data at 6-month and 12-month time points, using baseline data and 6-month outcome data if available. Predictive mean matching was used for the imputation with the ‘mice’ package for R statistical software [A longitudinal analysis, using generalised estimating equations (GEE), was used to assess differences between the groups in percentage weight loss over the 6-month and 12-month time points adjusting for baseline weight and a priori confounders. Secondary analyses compared changes in body composition, blood pressure and health behaviours (Mediterranean diet score, physical activity, alcohol intake and smoking behaviour) at 12-months, using ANCOVA and adjusting for baseline measurements.The main analyses were on an intention-to-treat basis using R version 4.0.2 at the 5% significance level unless otherwise stated. Sensitivity analyses checked the missing at random assumption by comparing treatment effects for completers only and a baseline observation carried forward analysis, and explored differences in baseline characteristics between women who completed vs those who did not complete the trial.