Intervention
Note that, for this particular study, the sample was pooled in just one group. This decision is based on the fact that there were no differences between the intervention arms (the main outcomes paper is under review). As such the description below is to inform of the overall format and content of the intervention; this ancillary study will not compare the impact of the different intervention contents, thus it is observational in nature.The NoHoW study was a digital behavior change, evidence-based, intervention. In summary, participants were randomized to one of four groups that accessed different digital contents to develop weight regain prevention behaviors: the NoHoW Toolkit. The four groups of the 2 × 2 factorial design were: 1) control; 2) motivation and self-regulation; 3) emotion regulation; and 4) motivation and self-regulation plus emotion regulation.In addition, all participants received commercial wireless body weight scales (Fitbit Aria), activity trackers (Fitbit Charge 2), and had access to a dashboard with physical activity, sleep, and weight data, which allowed for visualizing long-term progress and enabled simple self-assessments of mood and satisfaction with diet, sleep, activity, and weight as star ratings (1 to 5 stars), and entering free text personal notes into a diary.The participants in the three intervention arms received intervention content in the form of weekly sessions displayed in the Toolkit as an interactive map. The motivation and self-regulation arm had 17 sessions, the emotion regulation arm also had 17 sessions, and the combined arm had 34 sessions. Intervention participants were encouraged to complete the intervention sessions during the first 18 weeks of the trial. This was achieved by sending participants weekly emails during this time to introduce the weekly themes and remind them to visit the Toolkit. The control arm also received weekly emails for the first 18 weeks, but they only contained links to generic weight management content. A detailed description of the Toolkit is presented by Marques et al. [