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NCT Number: NCT06382480

PROTeIn-rich Meals to Control Glucose

The overall aim is to identify the dietary pattern for prevention and treatment of type 2 diabetes. The specific aim of this pilot project is to compare effects of two diets with different diurnal distribution of carbohydrates and protein on the glucose metabolism in subjects with prediabetes and type 2 diabetes and its effects on inflammatory status.

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Key information

Conditions

Overweight Body Weight Diabetes Mellitus Diabetes Mellitus, Type 2 Endocrine System Diseases Glucose Metabolism Disorders Metabolic Diseases Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Pathological Conditions, Signs and Symptoms PreDiabetes Prediabetic State Signs and Symptoms Type 2 Diabetes

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

About this study

Overweight individual with prediabetes and non-insulin treated type 2 diabetes will be recruited for the study. The trial will have a cross-over design and compare metabolic effects of two isocaloric 4-week interventions with opposite timely distribution of macronutrient intake - a high-protein (HP) breakfast and a high-carb (HC) dinner (HP/HC intervention) vs. a HC breakfast and a HP dinner (HC/HP intervention) - divided by a 4-week wash-out phase. A HP low-carb meal (breakfast or dinner) will contain 35%E protein, 35%E carbs, and 30%E fat, and a HC meal (breakfast or dinner) will contain 10E%protein, 60%E carbs, and 30%E fat.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Prediabetes (fasting blood sugar 100-125 mg/dl)
  • Diabetes type 2 (fasting blood sugar >126 mg/dl)
  • Overweight and obesity (BMI 25-50 kg/m2)

Exclusion criteria

  • Other diabetes types
  • Insulin treatment
  • Shift work
  • Weight changes >5% within past 3 months
  • Systemic glucocorticoid therapy
  • Systemic infections
  • Severe anemia
  • High blood pressure (>180/110 mmHg)
  • Endocrinologic, liver and heart disorders
  • Immune diseases
  • Thyroid dysfunction
  • Heart attack or stroke
  • Cancer in the last 2 years
  • Eating disorders, food intolerance/allergy, addiction disorders, digestive disorders intestinal, liver, cardiovascular diseases
  • Hereditary or acquired coagulation disorders
  • Non-interruptible intake of blood thinners (anticoagulants)
  • Specific diets, intermittent fasting
  • Pregnancy or breastfeeding
  • Severe internal or psychiatric disorders or other conditions and drugs therapy that might influence the outcome of the study

Treatment and study plan

Diet with specific macronutrient composition.

Other

The intervention is about an isocaloric diet that differs in terms of distribution of carbohydrates and protein throughout the day. The interventions include a HP-breakfast and a HC-dinner vs. a HC-breakfast and a HP-dinner. A HP low-carb meal (breakfast or dinner) will contain 35%E protein, 35%E carbs, and 30%E fat, and a HC meal (breakfast or dinner) will contain 10%E protein, 60%E carbs, and 30%E fat.

Primary outcomes

  1. Mean 24-hour glucose

    Time frame: 4 weeks

    Mean 24-hour glucose assessed by continuous glucose monitoring (CGM)

Secondary outcomes

  1. Measurement of height

    Time frame: 4 weeks

    Height measured by stadiometer

  2. Measurement of body weight

    Time frame: 4 weeks

    Body weight measured by body scale

  3. Waist and hip circumference / waist to hip ratio

    Time frame: 4 weeks

    Waist and hip circumference measured by tape measure

  4. Systolic and diastolic blood pressure

    Time frame: 4 weeks

    Systolic and diastolic blood pressure changes measurement by manometer

  5. Body fat and lean mass

    Time frame: 4 weeks

    Body fat and lean mass assessed by bioelectrical impendance analysis (BIA)

  6. Energy expenditure and substrate oxidation rates

    Time frame: 4 weeks

    Energy expenditure and substrate oxidation rates assessed by indirect calorimetry

  7. Hepatic values (gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), alanine aminotransferase (ALT))

    Time frame: 4 weeks

    GGT, AST, ALT etermined in fasting blood samples

  8. Renal values (creatinine, urea, uric acid)

    Time frame: 4 weeks

    Renal values determined in fasting blood samples

  9. Intra- und inter-day glycemic variability

    Time frame: 4 weeks

    Indices of intra- and inter-day glycemic variability assessed by continuous glucose monitoring (CGM)

  10. Glucose levels in meal tolerance test (MTT)

    Time frame: 4 weeks

    Glucose levels in blood samples collected in MTT

  11. Metabolic hormones (insulin, C-peptide, glucagon, glucagon-like peptite 1(GLP-1), gastric inhibitory polypeptide (GIP), peptide YY (PYY), ghrelin, adiponectin, leptin)

    Time frame: 4 weeks

    Blood levels of metabolic hormones assessed in fasting state and during the MTT

  12. Inflammatory markers and T cell populations analyses

    Time frame: 4 weeks

    Level of the inflammatory markers IL-6, TNFa, MCP-1 and T cell populations in circulation and adipose tissue are assessed through blood analysis and fat biopsy

  13. Satiety and hunger scores

    Time frame: 4 weeks

    Satiety and hunger scores assessed using Visual Analog Scale (VAS with a scale of 1-100, where higher values correspond to stronger satiety/hunger)

  14. Sleep/wake timing and sleep quality

    Time frame: 4 weeks

    Sleep/wake timing and sleep quality assessed by the Pittsburgh Sleep Quality Index (PSQI score, which ranges from 0-21, where higher values correspond to worse sleep quality) and also monitored by an ActiGraph device

  15. Physical activity

    Time frame: 4 weeks

    24-h physical activity will be monitored by an ActiGraph device

  16. Adipose tissue transcriptome

    Time frame: 4 weeks

    RNA-Seq analysis of subcutaneous adipose tissue sample

  17. Gene expression in peripheral blood mononuclear cells (PBMC)

    Time frame: 4 weeks

    Expression of metabolic genes assessed by qPCR

  18. Gut microbiota and microbiome-derived metabolites

    Time frame: 4 weeks

    Determined in stool samples and blood plasma

  19. Determination of decision behavior

    Time frame: 4 weeks

    Impulsiveness assessed by decision making tasks on computer

Study contacts

Contact information is provided by the study sponsor or research team.

Marina D´Urso

CONTACT

[email protected]

+4933200882690

Olga Ramich, PD Dr.

CONTACT

[email protected]

+4933200882749

Sponsors and collaborators

Lead sponsor

German Institute of Human Nutrition

Other

Collaborators

  • Charite University, Berlin, Germany
  • Hasso Plattner Institute, Potsdam, Germany
  • Helmholtz Center Munich

Registry information

Official study title

Meal Timing-based Strategies to Improve Glucose Metabolism in Prediabetes and Type 2 Diabetes

Acronym: PROTIME

Important dates

Study start
2024
Primary completion
2026
Study completion
2027
First posted
Apr 24, 2024
Registry last updated
Aug 26, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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