Background & Objective: Dietary management remains the first-line treatment for obesity. This qualitative study aimed to explore participants’ experiences in a six-month controlled weight loss intervention with set meal plans, following either an intermittent fasting (IF) diet or daily calorie restriction (CR), and a two-month follow-up period, to better understand factors that promote sustained dietary change.
Methods: Fifteen participants with overweight or obesity, who completed or dropped out from the two intervention groups, were recruited using purposive sampling. In-depth, semi-structured interviews were conducted during the 2-month follow-up phase. All interviews were audio-recorded and transcribed verbatim. Transcripts were coded by two independent researchers and analysed thematically.
Results: Interviews from the two intervention groups showed similar behaviour change patterns. Participants first joined the weight loss trial with varied levels of intrinsic motivation to improve health, but relied more on “accountability” to researchers for early dietary adherence. They stressed the importance of frequent visits with researchers and being monitored with objective clinical measurements. Such feedback mechanisms either encouraged dietary adherence or prompted self-review. Meanwhile, it was highlighted that transition to the new diet took time and effort. Participants who worked with researchers to adjust to their prescribed diet showed more positive attitudes towards the intervention. This reflected an ownership of self-care and sustaining adherence to new diets. However, those who continued to rely on the frequent visits with researchers to be disciplined were more likely to report returning to usual dietary habits once the intervention finished.
Conclusion: Our findings demonstrated that individuals successfully making and maintaining the prescribed dietary changes underwent a transition of being accountable under supervision to owning the intervention themselves. This process not only required initial motivation, but frequent external monitoring and feedback along the way that prompts participant’s adjustment of the new diet to fit their lifestyle.