Supporting Weight Management during COVID-19 (SWiM-C): twelve-month follow-up of a randomised controlled trial of a web-based, ACT-based, guided self-help intervention.

OBJECTIVES: We developed a guided self-help intervention (Supporting Weight Management during COVID-19, "SWiM-C") to support adults with overweight or obesity in their weight management during the COVID-19 pandemic. This parallel, two-group trial (ISRCTN12107048) evaluated the effect of SWiM-C on weight and determinants of weight management over twelve months. METHODS: Participants (≥18 years, body-mass-index ≥25 kg/m2) were randomised to the SWiM-C intervention or to a standard advice group (unblinded). Participants completed online questionnaires at baseline, four months, and twelve months. The primary outcome was change in self-reported weight from baseline to twelve months; secondary outcomes were eating behaviour (uncontrolled eating, emotional eating, cognitive restraint of food intake), experiential avoidance, depression, anxiety, stress, wellbeing and physical activity. INTERVENTIONS: SWiM-C is based on acceptance and commitment therapy (ACT). Participants had access to an online web platform with 12 weekly modules and email and telephone contact with a trained, non-specialist coach. Standard advice was a leaflet on managing weight and mood during the COVID-19 pandemic. RESULTS: 388 participants were randomised (SWiM-C: n = 192, standard advice: n = 196). The baseline-adjusted difference in weight change between SWiM-C (n = 119) and standard advice (n = 147) was -0.81 kg (95% CI: -2.24 to 0.61 kg). SWiM-C participants reported a reduction in experiential avoidance (-2.45 [scale:10-70], 95% CI: -4.75 to -0.15), uncontrolled eating (-3.36 [scale: 0-100], 95% CI: -5.66 to -1.06), and emotional eating (-4.14 [scale:0-100], 95% CI: -7.25 to -1.02) and an increase in physical activity (8.96 [MET-min/week], 95% CI: 0.29 to 17.62) compared to standard advice participants. We found no evidence of an effect on remaining outcomes. No adverse events/side effects were reported. CONCLUSIONS: Whilst we were unable to conclude that the intervention had an effect on weight, SWiM-C improved eating behaviours, experiential avoidance and physical activity. Further refinement of the intervention is necessary to ensure meaningful effects on weight prior to implementation in practice. TRIAL REGISTRATION NUMBER: ISRCTN 12107048.

Supporting Weight Management During COVID (SWiM-C): A Randomized Trial of an ACT-Based Intervention

Background: We developed a web-based, acceptance-based, guided self-help intervention (Supporting Weight Management during COVID-19, "SWiM-C") which aimed to support adults with over-weight or obesity in their weight management and emotional well-being during the COVID-19 pandemic. This study evaluates the effect of SWiM-C on weight and determinants of weight over twelve months. Methods: We randomized 388 participants (>18 years, BMI >25kg/m2) to the SWiM-C intervention (n=192) or a control group (n=196). SWiM-C is based on acceptance and commitment therapy (ACT) and is delivered remotely via an online web platform (12 weekly modules) and contact via telephone and email with a trained, non-specialist coach. The control group received a leaflet on weight management and wellbeing during the pandemic. Participants completed online questionnaires at baseline, 4 months, and 12 months. The primary outcome was change in self-reported weight from baseline to 12 months;secondary outcomes were eating behavior, experiential avoidance, mental health, wellbeing and physical activity. Results: At 12 months, the adjusted difference in weight between SWiM-C and control group participants was -0.81kg (95% CI: -2.24 to 0.61kg). SWiM-C participants reported a greater reduction in experiential avoidance (-2.45, 95% CI: -4.75 to -0.15), uncontrolled eating (-3.36, 95% CI: -5.66 to -1.06), and emotional eating (-4.14, 95% CI: -7.25 to -1.02), and an increase in physical activity (8.96, 95% CI: 0.29 to 17.62) compared to the control group. No differences in mental health or wellbeing were observed at 12 months. Conclusions: Whilst the effect of the SWiM-C intervention on weight was inconclusive, SWiM-C improved eating behaviors, physical activity and psychological flexibility. These variables have been previously identified as determinants of successful weight management. Further refinement of the intervention is necessary to ensure meaningful effects on weight prior to implementation in practice. By being remotely delivered using non-specialists, SWiM-C enhances scalability and population reach while minimizing cost.

Supporting Weight Management during COVID-19: A Randomized Controlled Trial of a Web-Based, ACT-Based, Guided Self-Help Intervention.

INTRODUCTION: Adults with overweight and obesity are vulnerable to weight gain and mental health deterioration during the COVID-19 pandemic. We developed a web-based, guided self-help intervention based on Acceptance and Commitment Therapy (ACT) that aims to support adults with overweight and obesity to prevent weight gain by helping them to manage their eating behaviours, be more physically active, and protect their emotional wellbeing ("SWiM-C"). SWiM-C is a guided self-help programme using non-specialist guides to enhance scalability and population reach while minimizing cost. This study evaluated the effect of SWiM-C on bodyweight, eating behaviour, physical activity, and mental wellbeing in adults with overweight and obesity over 4 months during the COVID-19 pandemic in the UK. METHODS: We randomized adults (BMI ≥25 kg/m2) to SWiM-C or to a wait-list standard advice group. Participants completed outcome assessments online at baseline and 4 months. The primary outcome was self-measured weight; secondary outcomes were eating behaviour, physical activity, experiential avoidance/psychological flexibility, depression, anxiety, stress, and wellbeing. We estimated differences between study groups in change in outcomes from baseline to 4 months using linear regression, adjusted for outcome at baseline and the randomization stratifiers (BMI, sex). The trial was pre-registered (ISRCTN12107048). RESULTS: 486 participants were assessed for eligibility; 388 participants were randomized (196 standard advice, 192 SWiM-C), and 324 were analysed. The adjusted difference in weight between SWiM-C and standard advice was -0.60 kg (-1.67 to 0.47, p = 0.27). SWiM-C led to improvements in uncontrolled eating (-3.61 [-5.94 to -1.28]), cognitive restraint (5.28 [2.81-7.75]), experiential avoidance (-3.39 [-5.55 to -1.23]), and wellbeing (0.13 [0.07-0.18]). CONCLUSIONS: SWiM-C improved several psychological determinants of successful weight management and had a protective effect on wellbeing during the pandemic. However, differences in weight and some other outcomes were compatible with no effect of the intervention, suggesting further refinement of the intervention is needed.