Impact of intermittent fasting on self‐regulatory behaviour and sleep in participants with insulin‐treated type 2 diabetes: A secondary analysis of the INTERFAST‐2 randomised controlled trial

external stimuli and stressors.It is closely linked to self-regulation, self-efficacy, and associated with a lower number of bodily complaints.7 IF may strengthen this competence by modulating stressresponse pathways, enhancing interoceptive awareness, and supporting mood regulation.8 Psychological and personality-related factors play a key role in treatment adherence in chronic conditions such as type 2 diabetes (T2D), where psychotherapeutic interventions can meaningfully improve outcomes.9 Sleep quality, vital for health, is influenced by eating behaviour and circadian timing.IF could stabilise rhythms and improve sleep, though results remain mixed.10 Effective T2D management requires consistent self-regulation across diet and exercise domains.Recent findings suggest that IF may facilitate this by inducing an "intermittent metabolic switch" from glucose to ketone utilisation, which promotes a broader metabolic recalibration. 3 While IF and CR are comparably effective for long-term weight loss (≥6 months), the high adherence rates often seen in TRF protocols (up to 95%) suggest it may be a sustainable selfregulatory tool for many patients.6,11 Furthermore, integration of exercise with IF is crucial, as it not only enhances visceral fat loss but also preserves lean body mass and cardiorespiratory fitness, addressing the physiological plateaus that often hinder long-term adherence.12 This secondary analysis examines the effects of a 12-week IF intervention on psychosomatic competence and sleep quality in insulin-treated patients with T2D, expanding the understanding of IF's broader impact in this metabolic high-risk group.