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.

University of Zaragoza

Status: Enrolling

Conditions: Overweight or Obesity; Type 2 Diabetes; PreDiabetes

Treatments: Other: Diet

Study type: Interventional

Funder types: Other

Identifiers

NCT06912555

PI23/558

Details and patient eligibility

About

Background and 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.

Enrollment: 120 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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 could interfere with lipid and/or glucose metabolism, unless taken stably throughout the study.
• Consumption of sleep supplements, except for stable use for 6 months with the intention to continue stable use throughout the study.
• Presence of any laboratory abnormalities that could affect study results.
• Weight gain or loss of ≥ 5% in the last 3 months.
• Use of vitamin supplements in an unstable manner for at least 6 months prior to study entry.
• High intake of alcohol (> 30 g of ethanol) on a regular basis.
• Pregnancy or intention to become pregnant during the study.
• Severe illness of any kind with a life expectancy of less than 1 year or that, in the investigators' judgment, limits uniform dietary intake throughout the study.
• Any other circumstance that, in the investigators' judgment, would impede adequate adherence to the proposed nutritional intervention (e.g., frequent travel during the study, inability to attend visits due to personal or work-related circumstances, etc.).

Trial design

Primary purpose: Supportive Care

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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120 participants in 3 patient groups

A. Low-calorie and high-protein diet with high-protein dinner (60% of total daily protein)

Experimental group

Description:

The macronutrient distribution will be initially based on a protein intake of 1.3-1.5 g/kg of body weight. From this protein intake, the total calorie intake will be calculated, and 30% of these calories will be allocated to fat consumption. The remaining calories will be allocated to carbohydrate consumption, depending on the amount of protein consumed. The protein will be distributed as follows: breakfast and lunch (\~40%), and dinner (\~60%). The caloric restriction will be moderate, involving a reduction of 30% of the total energy expenditure, specifically calculated for each individual. This reduction will result in approximately 400-600 kcal decrease per day compared to the participant's usual energy needs. It is important to note that the caloric content of the diet will never be less than 1200 kcal per day, as such a diet may not meet the participant's nutritional requirements.

Treatment:

Other: Diet

Other: Diet

Other: Diet

B. Low-calorie and high-protein diet with low-protein dinner (15% of total daily protein)

Experimental group

Description:

The macronutrient distribution will be initially based on a protein intake of 1.3-1.5 g/kg of body weight. From this protein intake, the total calorie intake will be calculated, and 30% of these calories will be allocated to fat consumption. The remaining calories will be allocated to carbohydrate consumption, depending on the amount of protein consumed.The protein will be distributed as follows: breakfast and lunch (\~85%), and dinner (\~15%). The caloric restriction will be moderate, involving a reduction of 30% of the total energy expenditure, specifically calculated for each individual. This reduction will result in approximately 400-600 kcal decrease per day compared to the participant's usual energy needs. It is important to note that the caloric content of the diet will never be less than 1200 kcal per day, as such a diet may not meet the participant's nutritional requirements.

Treatment:

Other: Diet

Other: Diet

Other: Diet

C. Low-calorie and regular-protein diet

Experimental group

Description:

The macronutrient distribution will be initially based on a protein intake of 0.8 g/kg of body weight. From this protein intake, the total calorie intake will be calculated, and 30% of these calories will be allocated to fat consumption. The remaining calories will be allocated to carbohydrate consumption, depending on the amount of protein consumed. The caloric restriction will be moderate, involving a reduction of 30% of the total energy expenditure, specifically calculated for each individual. This reduction will result in approximately 400-600 kcal decrease per day compared to the participant's usual energy needs. It is important to note that the caloric content of the diet will never be less than 1200 kcal per day, as such a diet may not meet the participant's nutritional requirements.

Treatment:

Other: Diet

Other: Diet

Other: Diet