Evaluation of an internet based weight loss intervention

Abstract

Introduction: The increasing obesity epidemic requires investigation of the effectiveness, cost-effectiveness and scalability of alternative delivery methods for weight loss interventions, such as via the internet. Aims/objectives: To examine characteristics, feedback format, engagement levels, behaviour change techniques used and effectiveness of individualised feedback within internet based weight loss interventions to refine a pre-existing private sector web-based platform ‘My dietitian online’. To pilot test this refined platform, to investigate its feasibility and acceptability of this refined platform for delivery in primary care and to inform the design and conduct of a future definitive RCT. To describe website use and explore health professionals’ and participants’ views and perceptions of the intervention in terms of acceptability, feasibility and usability. Methods: (i) Systematic review of the components and effectiveness of individualised feedback within internet based weight loss interventions. (ii) A 12-month rehearsal pilot randomised controlled trial (RCT) of an internet based dietary and physical activity intervention in two population groups, with collection of data on anthropometric measures, diet, physical activity, quality of life and predictors of behaviour change. The main focus of the trial was on feasibility, including recruitment and retention rates. (iii) A mixed-methods qualitative process evaluation conducted alongside the pilot RCT comprising analysis of website usage and semi-structured interviews with participants and healthcare professionals to explore their experience of the intervention. Results The systematic review identified 14 studies. Interventions with individualised feedback led to more weight loss than those with no feedback. Studies examining different modalities of weight loss intervention were very limited. In the pilot trial 61 men with diabetes and 16 post-partum women were recruited. At 12 months retention rates for men were 61% in the intervention arm, 53% in the control arm, and for women were 53% in the intervention arm and 54% in the control arm. Website usage varied greatly between intervention participants, with 49% and 57% of men and women ii respectively ever using the website. The semi-structured interviews revealed that participants and health professionals saw an internet based intervention as an appropriate method to implement within the NHS for weight loss, with the suggestions made for integration with current services. Conclusion High attrition rates along with low adherence to the intervention were identified. Possible refinements to the website were suggested to reduce the burden and time requirements for users.