Aim: This qualitative study aimed to explore the experiences of participants who were enrolled in 6-month controlled weight loss interventions with 2-month follow-up to better understand the process of behaviour change and maintenance.
Methods: Fifteen participants who completed or dropped out from either a daily energy restriction or intermittent fasting group were recruited using maximum variation purposive sampling. In-depth, semi-structured interviews were conducted at the 2-month follow-up phase. All interviews were transcribed and analysed using thematic analysis, guided by behaviour change models including transtheoretical model, social cognitive theory and integrated model of change.
Results: Participants following both diets showed similar behaviour change patterns. Their first motivations were mostly external and relied on 'accountability' to adhere to the diet when initiating the dietary changes. Participants highlighted the importance of frequent reviews and monitoring in assisting their adherence. This feedback system promoted the development of self-efficacy and internalised motivation to encourage an 'ownership'. Participants who transitioned successfully from relying on accountability to take 'ownership' of the intervention were more capable of tackling challenges and tailoring their diet to form a new routine for long-term maintenance.
Conclusion: External motivations were key to initiate while internalised motivations were more important to sustain the behaviour change. Health professionals can assist this process through routine monitoring and feedback processes in clinical practice.
Keywords: behaviour change; dietary intervention; implementation science; obesity; overweight; qualitative study.
© 2023 The Authors. Nutrition & Dietetics published by John Wiley & Sons Australia, Ltd on behalf of Dietitians Australia.