Precise Eating Time to Improve Glycemic Control and Cardiometabolic Health in Prediabetes and Diabetes

Not Applicable

Recruiting

• Conditions: Prediabetes; Type 2 Diabetes; Obesity &Amp; Overweight

• Registration Number: NCT07171281
• Lead Sponsor: German Institute of Human Nutrition

Brief Summary

The objective of this study is to investigate the impact of hypocaloric time-restricted eating (TRE) at different day times (early versus late TRE) on glucose metabolism and other cardiometabolic parameters in individuals with overweight and with normal, or impaired glucose metabolism (prediabetes and type 2 diabetes). In addition, the study aims to elucidate the molecular mechanisms underlying these effects.

Detailed Description

This dietary intervention study will follow a crossover design. During the intervention phases, participants will restrict their dietary intake to a defined eating window of 8 hours - predominantly in the morning (early TRE) or predominantly in the afternoon (late TRE) - in conjunction with a moderate caloric restriction for five weeks. A 10-12-week washout phase will separate the intervention periods.

Overweight and obese individuals with healthy glucose metabolism, prediabetes, or non-insulin-treated type 2 diabetes will be recruited for the study.

Study Timeline

• Study First Submitted: 2025-08-26
• Status Verified: 2025-09
• Study First Submitted QC: 2025-09-10
• Last Update Submitted: 2025-09-10
• Study First Posted: 2025-09-12
• Last Update Posted: 2025-09-12
• Study Start: 2025-09-19
• Primary Completion: 2027-12-31
• Study Completion: 2028-02-28

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 30

Inclusion Criteria

• Overweight or obesity (BMI 25-40 kg/m²)
• Healthy glucose metabolism (fasting glucose <100 mg/dl and glucose after 2 hours OGTT <140 mg/dl)
• OR impaired glucose metabolism (fasting glucose 100-125 mg/dl and/or glucose after 2 hours OGTT 140-199 mg/dl and/or HbA1c 5.7-6.4%)
• OR type 2 diabetes (according to existing medical diagnosis or fasting glucose >126 mg/dl and/or glucose after 2 hours OGTT >200 mg/dl and/or HbA1c ≥6.5%)
• Daily eating window ≥12 hours

Exclusion Criteria

• Weight changes > 5% within past 3 months
• Shift work
• Traveling across more than one time zone within one month prior to the study
• Pregnancy and breastfeeding
• Eating disorders, food intolerance/allergy to ingredients in the diet product, vegan diet, practicing time-restricted eating
• Severe chronic illnesses or other conditions that are incompatible with the planned intervention and examination program (e.g. type 1 diabetes, recent cardiovascular event, malabsorption, cancer in the last two years, etc.)
• Treatment with insulin, sulfonylureas, and GLP-1 receptor agonists, steroid use (oral, cutaneous, or parenteral), regular intake of melatonin, anticoagulation treatment that cannot be paused
• Extreme early and extreme late chronotypes

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Mean 24-hour glucose	5 weeks	Mean 24-hour glucose assessed by continuous glucose monitoring (CGM)

Secondary Outcome Measures

Name	Time	Method
Waist and hip circumference	5 weeks	Waist and hip circumference \[cm\] measured by tape
Body composition	5 weeks	Body fat mass and lean mass \[kg\], as measured by bioelectrical impendance analysis (BIA)
Glycemic variability	5 weeks	Inter- and intraday indices of glycemic variability assessed by CGM
Glucose levels	5 weeks	Fasting and postprandial glucose \[mg/dL\] in response to a mixed meal tolerance test
Insulin levels	5 weeks	Fasting and postprandial insulin \[mU/L\] in response to a mixed meal tolerance test
Glucagon levels	5 weeks	Fasting and postprandial glucagon \[pmol/L\] in response to a mixed meal tolerance test
Insulin resistance	5 weeks	Insulin resistance, as assessed by HOMA-IR \[AU\]
Insulin secretion	5 weeks	Insulin secretion, as assessed with the insulinogenic index \[AU\]
Body weight	5 weeks	Body weight \[kg\], as measured by scale weight
Body Mass Index (BMI)	5 weeks	BMI \[kg/m2\], calculated as weight/square height
Fasting cholesterol	5 weeks	Fasting total cholesterol, low-density lipoprotein and high-density lipoprotein cholesterol \[mmol/L\]
Fasting triglycerides	5 weeks	Fasting triglycerides \[mmol/L\]
Blood pressure	5 weeks	Systolic and diastolic blood pressure \[mm Hg\], as measured by manometer
Resting energy expenditure	5 weeks	Resting energy expenditure \[kcal/day\], as assessed by indirect calorimetry
Gene expresssion in adipose tissue	5 weeks	RNAseq analysis of subcutaneous adipose tissue samples
Inflammatory markers in blood and adipose tissue	5 weeks	Levels of adipokines and inflammatory markers measured in blood samples and subcutaneous adipose tissue samples
Subjective satiety and hunger sensation	5 weeks	Satiety and hunger scores assessed using Visual Analog Scales (VAS, with a scale of 1-100, where higher values correspond to stronger satiety/hunger)
Concentration of satiety and hunger regulating hormones	5 weeks	Levels of ghrelin and peptide YY (PYY), as measured in blood samples in \[pg/mL\]
Species and strain-level microbiome changes	5 weeks	Species and strain-level microbiome changes, as assessed by 16S rRNA gene sequencing of stool samples
Levels of microbiome-derived metabolites	5 weeks	Levels of microbiome-derived metabolites measured in stool samples and blood plasma
Sleep quality	5 weeks	Sleep quality as 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
Sleep and wake timing	5 weeks	Sleep onset and offset assessed by the Pittsburgh Sleep Quality Index (PSQI score, which ranges from 0-21, where higher values correspond to worse sleep quality) and in addition by using a sleep diary
Internal circadian phase	Screening visit (week 0)	Internal circadian phase as assessed using the BodyTime assay in peripheral mononuclear blood cells (PBMCs)
Glucagon-like peptide-1 levels	5 weeks	Fasting and postprandial glucagon-like peptide-1 (GLP-1) in response to a mixed meal tolerance test \[pM\]
Gastric inhibitory polypeptide	5 weeks	Fasting and postprandial gastric inhibitory polypeptide (GIP) in response to a mixed meal tolerance test \[pg/mL\]
Gene expresssion in peripheral mononuclear blood cells (PBMCs)	5 weeks	RNAseq analysis of clock, metabolic and inflammatory gene expression peripheral mononuclear blood cells (PBMCs)
Malondialdehyde	5 weeks	Plasma malondialdehyde \[µmol/L\]
3-nitrotyrosine	5 weeks	Plasma 3-nitrotyrosine \[pmol/mg\]
Protein carbonyls	5 weeks	Plasma protein carbonyls \[nmol/mg\]
36-item Short Form Health Survey (SF-36) to measure health-related quality-of-life	5 weeks	Health-related quality-of-life, as assessed by the 36-Item Short Form Health Survey (SF-36, with scores ranging from 0 to 100, with a higher score defining a more favorable health state)
Satisfaction with the intervention	5 weeks	Satisfaction with the intervention assessed by a 5-point Likert scale (with 5 representing "Very satisfied" and 1 representing "Very dissatisfied")
Decision behavior	5 weeks	Impulsiveness assessed by decision making tasks on computer

Trial Locations

Locations (1)

German Institute of Human Nutrition Potsdam-Rehbruecke; 🇩🇪 Nuthetal, Germany

German Institute of Human Nutrition Potsdam-Rehbruecke

🇩🇪Nuthetal, Germany

Olga Ramich, Prof. Dr.

Contact

+49 33200 882749

olga.ramich@dife.de

Bettina Schuppelius, M.Sc.

Contact

+49 33200 882692

bettina.schuppelius@dife.de