Accepted for/Published in: Journal of Medical Internet Research
Date Submitted: Dec 16, 2019
Date Accepted: Oct 3, 2020
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Weight loss and dietary behaviour change program delivered by web platform with and without dietitian online coaching compared to minimal intervention for adults with overweight and obesity in the community: the POEmaS randomized controlled trial.
ABSTRACT
Background:
The effectiveness of web-based weight loss programs outside healthcare settings, and the role of intervention personalization through a human component are unclear.
Objective:
We aimed to investigate the effectiveness of a web-based behaviour change intervention with and without online dietitian coaching to adults with overweight/obesity in the community.
Methods:
This pragmatic, three group, parallel arm, randomized controlled trial recruited students and staff, aged 18-60 years, with body mass index (BMI) ≥25 kg/m2 and access to internet in a Brazilian public university. Pregnancy and dietary restrictions were exclusion criteria. Participants were allocated either to the ‘Platform-only’ group (24-week behaviour change program delivered by a web-platform); or to the ‘Platform/ coaching’ group (same web-based 24-week behaviour change program plus a 12-week course of online dietitian coaching); or the ‘Waiting list’ group (non-personalized dietary and physical activity recommendations delivered through e-booklet and videos). Self-reported 12 and 24 week-weight and BMI change were primary outcomes. Changes in daily portions of vegetables and fruit, whole grains, ultra-processed foods and sweetened beverages, and user engagement after 24 weeks were the secondary outcomes.
Results:
Among the 1298 participants, 375 (28.8%) were lost to follow-up. In the intention to treat analysis, weight/ BMI loss were higher (p=0.04 for both) in the ‘Platform-only’ (-0.39 kg, SD1.70 and-0.14 kg/m2, SD0.64, respectively) and ‘Platform/coaching’ (-0.43 kg, SD2.03 and -0.15 kg/m2, SD 0.72, respectively) than in the ‘Waiting list’ group (-0.15 kg, S1.61 and -0.06 kg/m2, SD0.59, respectively) after 12 weeks, but not after 24 weeks (p=0.35). The daily intake of vegetables and fruit servings/day increased more importantly in the ‘Platform-only’ (0.50, SD1.30) than in the ‘Platform/coaching’ (0.16, SD1.44) and ‘Waiting list’ group (0.00, SD1.5; p=0.02). Other dietary habits did not differ across the groups. Engagement was higher in the ‘Platform/coaching’ than in the ‘Platform-only’ group (7.6 weeks, SD 11.4 versus 5.2 weeks, SD16.0).
Conclusions:
A web-based behaviour change program was effective for short-term weight/BMI loss and increase in fruits/vegetables intake in a community setting. The online dietitian coaching increased engagement and might be considered for individuals likely to abandon weight loss programs. Clinical Trial: US National Library of Medicine ClinicalTrials.gov NCT03435445 https://clinicaltrials.gov/ct2/show/NCT03435445
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