A Randomized Study to Investigate the 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.
Aims: Shift work, particularly involving night shifts, is associated with increased risk of metabolic disturbances such as type 2 diabetes mellitus (T2DM). Thus, it is important to explore mechanisms underlying this deleteroius effect and strategies that could prevent or mitigate it. The aim of the study is to investigate the effect of three low-calorie diets with different macronutrients composition and distribution along day on glucose metabolism and other health outcomes in overweight or obese shift workers with prediabetes or T2DM.
Methods: In this randomized controlled trial, 120 shift workers with a BMI \> 27.5 kg/m2 and diagnosed with prediabetes or T2DM will be recruited. The trial assesses three low-calorie diets effects on glucose metabolism, body composition, and health outcomes over 12 weeks. These diets include: A) high-protein dinner (60% of total daily protein), B) low-protein dinner (15% of total daily protein), and C) normoproteic diet.
• 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.