Effect of Low-calorie Diets With Different Macronutrient Composition and Macronutrient Distribution in Shift Workers With Prediabetes or Type 2 Diabetes and Overweight or Obesity.

Inclusion Criteria: * Body mass index (BMI) ranging between 27.5 and 40 kg/m2. * Presence of prediabetes (fasting glucose between 100-125 mg/dL and/or glycated hemoglobin between 5.7 and 6.4%) or type 2 diabetes mellitus (fasting glucose ≥ 126 mg/dL and/or glycated hemoglobin ≥ 6.5% and/or currently taking metformin), based on the criteria of the American Diabetes Association. * Engaged in shift work, including night shifts, for at least 1 year and intending to maintain this schedule in the upcoming months. * Provide written informed consent for voluntary participation in the study after reviewing the participant information sheet and addressing any resulting queries. Exclusion Criteria: * Treatment with antidiabetic medications (oral or subcutaneous) or insulin in the last 2 months, except for stable use of metformin or Dipeptidyl peptidase 4 (DPP-4) inhibitors for a minimum of 6 months. * Treatment with lipid-lowering agents in an unstable manner for at least 6 months prior to study entry. * Regular consumption of functional foods such as phytosterols or red yeast rice, which have a significant effect on lipid or glucose metabolism, in an unstable manner for at least 6 months prior to study entry. * Presence of other chronic conditions that are not well-controlled and could interfere with study outcomes, such as cardiovascular disease, renal disease, or liver disease. * Presence of uncontrolled endocrine disorders, including hypothyroidism. * Use of medications that coul…