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.

Summary

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.

Conditions

• Type 2 Diabetes
• Overweight or Obesity
• PreDiabetes

Interventions

OTHER

Diet

The nutritional plan will be initially based on a protein intake of 1.3 to 1.5 g per kilogram of body weight. From this, the total daily calorie intake is calculated, with 30% of the calories allocated to fats. The remaining calories will be assigned to carbohydrates, depending on the protein intake. Protein distribution will be approximately 40% at breakfast and lunch, and 60% at dinner. Caloric restriction will be moderate, reducing the total energy expenditure by 30%-calculated individually-which translates to an approximate decrease of 400 to 600 kcal per day compared to the participant's usual energy needs. It is important to note that the diet will never provide less than 1200 kcal per day to ensure that the minimum nutritional requirements are met.

OTHER

Diet

The macronutrient plan will include a protein intake of 1.3 to 1.5 g per kilogram of body weight. Based on this protein amount, the total daily caloric intake will be determined, allocating 30% of the calories to fat consumption. The remaining calories will be assigned to carbohydrates, proportional to the protein intake. Protein distribution will be approximately 85% during breakfast and lunch and 15% at dinner. The caloric restriction will be moderate, with a 30% reduction in total energy expenditure calculated individually, resulting in an approximate decrease of 400 to 600 kcal per day compared to the participant's usual energy needs. It is important to note that the diet will never contain fewer than 1200 kcal per day, ensuring that the participant's nutritional requirements are met.

OTHER

Diet

The macronutrient plan will include a protein intake of 0.8 g per kilogram of body weight. From this protein amount, the total daily calorie intake will be calculated, with 30% of the calories allocated to fats. The remaining calories will be assigned to carbohydrates, depending on the protein intake. Caloric restriction will be moderate, reducing the total energy expenditure by 30%-calculated individually-which translates to an approximate decrease of 400 to 600 kcal per day compared to the participant's usual energy needs. It is important to note that the diet will never contain fewer than 1200 kcal per day, ensuring that the participant's nutritional requirements are met.

Sponsors & Collaborators

• Hospital Miguel Servet

  collaborator OTHER

• Universidad de Zaragoza

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

SUPPORTIVE_CARE

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2024-09-01

Primary Completion

2025-08-31

Completion

2025-12-31

Countries

• Spain

Study Locations