Self-initiated lifestyle changes during a fasting-mimicking diet programme in patients with type 2 diabetes: a mixed-methods study

This study drew on the Fasting In diabetes Treatment trial, in which 100 participants with type 2 diabetes using metformin only or no medication were randomly assigned to a monthly 5-day Fasting Mimicking Diet (FMD) alongside usual care, or to usual care only, for twelve months. Diet quality and physical activity questionnaires were completed at baseline, six months and twelve months, and were available from 49 diet participants and 43 controls. Six focus groups were then held with twenty diet participants and analysed with the Theoretical Domains Framework.

The authors reported no differences in diet quality between the groups. They reported that total physical activity changed from 34.6 to 38.5 hours per week in the diet group and from 34.9 to 29.0 hours per week in the control group, a difference between the groups that reached statistical significance. In the focus groups they reported that individual participants perceived the diet as encouragement for minor lifestyle changes, named no barriers to behaviour change related to the diet, and described facilitators including greater awareness of the impact of lifestyle on health, better physical fitness and health improvement. The authors suggest the programme could be used as a teachable moment to prompt further lifestyle change.

The quantitative outcomes are self-reported questionnaire answers about diet and activity, not measured behaviour and not health outcomes. Questionnaires were returned by fewer than half of the diet participants, and the focus groups covered twenty of them, so the qualitative findings describe those individuals rather than the trial population. Participants were people with type 2 diabetes in primary care, not a general wellness population, and the study does not evaluate Prolon directly.