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Category: Project

Description: Introduction: Digital behaviour change interventions targeting diet and physical activity have the potential for public health gain; however, these interventions are often not adequately tailored to the needs of participants. The aim of this study is to develop and test a digital intervention to help people make sustainable changes to diet and physical activity, and consequently their weight. This hybrid trial aims to determine the effectiveness and cost-effectiveness and evaluate implementation of the Choosing Health program as a means to promote weight loss maintenance among overweight/obese adults. Methods and analysis: This study is a two-group randomised controlled trial (RCT) with a nested interrupted time series (ITS) within-person design. Participants (N=285) will be randomly assigned to either the Choosing Health digital intervention or a control group. For intervention participants, Ecological Momentary Assessment (EMA) will be used to identify behavioural determinants for each individual in order to tailor evidence-based behaviour change techniques and intervention content. Control group participants will receive non-tailored factual weight loss advice. The primary outcome is mean difference in weight loss between groups at 6 months. Secondary outcomes include device measured blood pressure, percentage of body fat; self-reported measures of physical activity, sitting time, quality of life, and theory-derived correlates of weight loss. Secondary outcomes will be measured at baseline, 3-, 6- and 12 months. The primary outcome for ITS will be daily weight loss plan adherence. Data will be analysed using regression models and time series analysis. Ethics and dissemination: Ethics approval was granted by Faculty of Psychology, SWPS University of Social Sciences and Humanities, Wroclaw, Poland, approval number 03/P/12/2019. The project results will be disseminated through structured strategy implemented in collaboration with the Ministry of Health.