Limitations and future studies
digital-only, Automaticity
STILL
Due to the absence of effects of the NoHoW intervention, the strength of the logic model pathways may have been diminished, thereby limiting the analytical capabilities of the study. In addition, we hypothesize that the dosage of the intervention, which consists of a digital-only behavioral change program comprising 17 digital sessions lasting approximately 5 to 10 min each over a span of 18 weeks, may not be sufficient to induce the expected motivational changes as outlined in the logic model. Therefore, it is important to acknowledge that this limitation hinders our analysis of the logic model and its associated theoretical rationale.Furthermore, it is important to note that the full logic model of the NoHoW includes various emotional regulation variables that were not taken into account in this analysis. While the project has gathered data on emotional-related measures, we chose not to include them in the current analysis due to the overwhelming complexity it would have introduced. The inclusion of these variables would have resulted in a large number of interactions that were difficult to interpret, leading us to make the decision to analyze the emotional-regulation aspect separately in another paper.The NoHoW study relied on questionnaires to measure psychosocial variables. The comprehensive logic model was translated into extensive measurement packages. Considering this extensiveness, we created two measurement sessions at each data collection point to reduce the participants' load. Even so, our process evaluation detected a few cases of participants stating that the psychometrics were demanding, albeit none declined to complete them. In addition, the internal consistency measures were good, signaling that the negative impact of extended measurements was limited.The discrete data collection points—at baseline, six, and 12-months—may have limited the analysis of the dynamics between the factors in the NoHoW logic model. We recognize that the discrete data collection points at baseline, six, and 12 months may have restricted our analysis of the interplay between factors in the NoHoW logic model. Additionally, there are overlapping change variables in the model. For instance, the motivational variables from 0–6 months partially overlap with the self-regulation variables from 0–12 months. The decision to use these specific timeframes was informed by the best available evidence during the planning phase of this study. We aimed to capture the full extent of changes in putative predictors for self-regulation measures and how the intervention from 0–6 months impacted motivational variables, which would be associated and potentially influencing self-regulation variables (0–12 months). Alternative options were thoroughly discussed (e.g., 0–6 motivational affecting 6–12 self-regulation), but we ultimately executed the plan, decided about one year before the writing of this study.The different sizes of the success groups, and measuring weight change within the subgroups may have led to a statistical artifact. The group who regained weight was larger, seconded by the maintenance, with the smaller group comprising the participants who successfully lost weight. However, this last group included 225 participants, a large enough sample to avoid Type I errors. A similar imbalance should be noted regarding the sex distribution. Still, the large sample included 293 men, and sex was included in the analytical models as a covariate, which limits this potential imbalance effect.Automaticity and habit – two variables mentioned in our hypothesis generation section—represented a confounding variable in our study, as we did not measure them. We suggest that future studies investigate this – measuring habits, motives, self-regulation, resources, and environmental and social influences, as people learn to maintain a behavior. We predict that such studies may show an increase in habits and a decrease in motives and self-regulatory processes in the successful participants.Conversely, this article's strengths lie in its large sample size and the analytical procedure. Data was gathered over 12 months from a controlled trial in three European countries, with validated and standardized methods used in all centers. While replication is necessary, the results may apply to several European regions, given the large samples collected in the three countries representing Scandinavia, the UK, and Southern Europe. The mediation analysis examines the mechanisms of action of the NoHoW – a complex intervention, providing results to aid future programs in preventing weight regain.