The Effect of Time-Restricted Eating in 24-hour Metabolic Homeostasis and Diurnal Rhythm

Inclusion criteria

• willing and able to give informed consent for participation in the study
• aged 35-75 years
• men and women
• body mass index 27-45 kg/m2
• fasting plasma glucose 5.6-6.9 mmol/L, or 2h OGTT plasma glucose 7.8-11.1 mmol/L or haemoglobin A1C 39-46 mmol/mol, homeostasis model assessment-insulin resistance (HOMA-IR) score ≥2.73
• self-reported habitual eating period ≥ 13 h per day

Exclusion criteria

• shift worker
• fasting >12 h/day more than once a week
• vegan
• > once a week no food intake after ~1800 h
• habitually waking up before ~0400 h and sleeping before ~2100 h
• unstable weight (>5% change the last 2 months)
• type 1 or 2 diabetes
• sleep disorder (individuals with well-controlled sleep apnoea)
• eating disorder
• cancer in last 5 years
• conditions that render subject unable to complete all testing procedures (including individuals with known allergies or contraindications to the medications used in this study)
• use of medications that affect the study outcome measures or increase the risk of study procedures and that cannot be temporarily discontinued (e.g., steroids, alpha- or beta-adrenergic blockers or agonists, etc.)
• smoking and illegal drug use
• pregnant or lactating
• gastrointestinal or bariatric surgery (except cholecystectomy and appendectomy)
• unable to grant voluntary informed consent or comply with the study instructions
• individuals with electromedical devices
• prisoners
• alcohol abuse