Accepted for/Published in: Journal of Medical Internet Research
Date Submitted: Dec 16, 2019
Date Accepted: Oct 3, 2020
Web-based personalized weight loss behaviour change program with and without dietitian online coaching compared to non-personalized 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 and the role of adding a human-delivered personalised online intervention 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, intention to lose weight, and access to the internet in a Brazilian public university. Pregnancy, dietary restrictions and undertaking other treatments for weight loss 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 personalised feedback delivered online by a dietitian); 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 change was the primary outcome. Changes in vegetables and fruit, whole grains, ultra-processed foods and sweetened beverages intake were secondary outcomes.
Results:
Among the 1298 participants, 375 (28.8%) were lost to follow-up. In the intention to treat analysis, weight loss at 12 and 24 weeks was higher in the ‘Platform-only’ (-1.14kg; 95%CI -1.42, -0.85, and -1.08 kg; 95%CI -1.41,-0.75, respectively) and ‘Platform/coaching’(-1.36 kg; 95%CI -1.65 to -0.80, and -1.57 kg; 95%CI -1.92,-1.22, respectively) groups than in the ‘Waiting list’ group (-0.56 kg; 95% CI -0.83, -0.30, and -0.66; 95%CI -0.98,-0.34, respectively). Vegetables (-3%; 95%CI -5, 0 versus 3%; 95%CI 1 , 6 versus 5%; 95%CI 2 ,8; p=0.001) and fruit intake (2%; 95%CI 0, 6 versus 9%; 95%CI 6 , 12 versus 6%; 95%CI 2 ,9; p=0.016) had a greater increase in the ‘Platform-only’ and ‘Platform/coaching’ than in the ‘Waiting list’ group. Ultra-processed food consumption reduced more in the platform (-18%; 95%CI -23, -13) and platform/coaching (-25%; 95%CI -30, -20) groups than in the control group (-12%; 95%CI-16, -8; p=0.005). Physical activity did not differ across the groups. Engagement was higher in the ‘Platform/coaching’ than in the ‘Platform-only’ group (7.6, SD 11.4 versus 5.2 completed sessions, SD16.0; p=0.002) and each day of platform usage was associated with an Odds ratio 1.02 (95%CI 1.01,1.04) of clinically meaningful (≥5%) weight loss.
Conclusions:
A web-based behaviour change program led to a small weight loss within 6 months, and improvement in multiple dietary habits. The human-delivered personalised feedback by the online dietitian coaching increased engagement, which was associated with clinically meaningful weight loss. Clinical Trial: NCT03435445
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