Behaviour change during dietary Type 2 diabetes remission: a longitudinal qualitative evaluation of an intervention using a very low energy diet

Aim To understand the process of behaviour change through the experiences of people with Type 2 diabetes engaged in an 8‐month diabetes remission intervention including a 2‐month weight loss phase with the use of a very low energy diet (VLED), and a 6‐month, structured weight maintenance phase. Methods Data were collected in three semi‐structured interviews at baseline, week 8 (end of the weight loss phase), and month 8 (end of the weight maintenance phase). Longitudinal inductive thematic analysis was used to analyse participants’ narratives and identify change over time. Results Eleven of 18 participants completed all three interviews. The following themes of change were identified in their narratives: (1) ‘Building behavioural autonomy’ as a process of growing confidence to engage in health behaviours that are independent of those of other people; (2) ‘Behavioural contagion’ describing how one's new health behaviours tend to affect those of other people; (3) ‘From rigid to flexible restraint’, reflecting the changes in attitudes and behaviours required for a successful adaptation from weight loss to weight maintenance; and (4) ‘Shift in identity’, representing changes in the participants’ perceptions of themselves. Conclusions This longitudinal qualitative study provided new insights into how behaviour change is experienced by people with Type 2 diabetes engaged on a weight management intervention using VLED, contributing to theoretical and practical understanding of weight management behaviours. The themes identify potential areas in which individuals can be supported in achieving dietary diabetes remission and long‐term maintenance of weight loss. What's new? Remission of Type 2 diabetes can be achieved through substantial weight loss. Very low energy diets are effective for weight loss and diabetes remission, but little is known about people's experiences with transition to weight maintenance, how weight loss and maintenance are related within people's narratives and contexts, and how behaviour change can be identified and supported in the weight management process. This longitudinal qualitative study identified four themes of change: behavioural autonomy, behavioural contagion, from rigid to flexible constraint, and a shift in identity. These contribute to theoretical and practical understanding of weight management behaviours over time.