Randomised Control Trial of Remote Access, Group-based Functional Imagery Training Versus NHS 12 Week Online Programme in the Community

In England two thirds of the population are overweight, as defined by a body mass index (BMI) of 25 kg/m2 or more and nearly half of these have obesity as defined by a BMI of 30 kg/m-2 or more. Subsequently healthcare costs increase alongside the increasing prevalence of obesity and overweight with approximately 1.8% of the National Health Services (NHS) government budget and around 7.1% of all deaths being attributed to elevated BMI in 2014. Alongside the increased health risk associated with obesity, perceived quality of life declines also with increasing BMI. Tackling the obesity epidemic could therefore lead to better physical and mental health amongst a high proportion of the population.

The rise in obesity over the last two decades has led to an increased need to support individuals to lose weight but also reduce intervention costs. A review of group interventions for tier 3 services (severe obesity/ those with co-morbidities) found that group interventions are a cost effective method of treatment which demonstrate good results in terms of weight loss. Including the role of behaviour change in weight management is vital in ensuring the adoption and maintenance of new, long term skills which will help support maintaining weight loss.

Functional Imagery Training (FIT) is a theoretically informed intervention that utilises clients' intrinsic motivation and mental imagery to elicit effective behaviour change. It uses the well- established, person-centred approach of motivational interviewing. The mental imagery exercises are designed to strengthen motivation, consolidate plans for change, and build the person's confidence that they can succeed. Research demonstrates the emotive power of mental imagery and the shift from short-term rewards to longer term goals. Delivered face to face, one-to-one, FIT has been shown to elicit behaviour changes to support weight loss over a sustained period of 12 months. The investigators conducted a randomised controlled trial of one-to-one FIT compared to motivational interviewing which demonstrated those in the FIT group experienced greater weight loss at 6 months post-allocation compared to the motivational interview group and continued weight loss for the FIT group only at 12m, 6 months after intervention ended. There is a need to establish if FIT remains efficacious and cost-effective when delivered to groups.

The investigators will conduct a randomised control trial to test group-based delivery of FIT using the virtual platform Zoom. The current climate surrounding the increased need for remote-accessed services has allowed the investigators to explore the potential use of FIT online. There are many benefits to remote access interventions including reduced costs and travel time for the patients, more convenience and flexibility for patients and the reduced amount of clinic time for practitioners and patients.