Participant Characteristics
A total of 1,267 participants were randomised to one of the three groups (211 brief intervention, 528 12-week, 528 52-week intervention). The majority of the recruited participants were women (67.8%) and of white ethnicity (89.7%). Weight data were available for 823 participants at the 1-year follow-up. At 5-year follow-up, weight data were available for 871 participants in total. Study-measured weight was available for 632 participants; weight data were extracted from GP records for 146 participants (11.5%) and collected by self-report from 93 participants (7.3%). No weight values were available for 396 (31.3%) of participants at the 5-year follow-up.Data were available at the 1- and 5-year follow-ups for 708 participants (55.5%, Table 