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The RepEAT Study: Individual Differences in Postprandial Glucose Responses and the Relation With Diet and Phenotype

The RepEAT Study: Individual Differences in Postprandial Glucose Responses and the Relation With Diet and Phenotype

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05456815
Acronym
RepEAT
Enrollment
63
Registered
2022-07-13
Start date
2022-08-26
Completion date
2022-12-13
Last updated
2023-07-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Glucose Metabolism, Postprandial Glucose Responses

Keywords

Postprandial, Glucose, Standardized diet, Continuous monitoring

Brief summary

Postprandial glucose responses are related to an increased risk of developing cardiometabolic diseases. Existing research recognizes the presence of inter-individual variation in postprandial glucose responses to the same meal or food product. However, the role of diet and phenotype in postprandial glucose responses is unclear. The primary objective of this study is to determine the variation in postprandial glucose responses to the same meals/food products and how this relates to the variation in postprandial glucose responses over a 9-week fully controlled dietary intervention within and between individuals. Our secondary objectives are to investigate the difference between postprandial glucose responses to original products and postprandial glucose responses to reformulated products, and to examine the relation between postprandial glucose responses and short-term well-being. In addition, we aim to study the relation between variation in postprandial glucose and phenotype, including immune function, cognitive performance, and microbiota composition. 63 apparently healthy men and women with a BMI of 25-40 kg/m2, aged 45-75 years will be included in the study, comprising a characterization period of 3 weeks and a completely controlled dietary intervention of 9 weeks. During these 9 weeks, glucose will be continuously monitored to measure postprandial glucose responses to standard foods/meals. There are minor risks for the research subjects of this study. Research subjects will invest approximately 85 hours in the study. During the characterization week, subjects will visit the Wageningen University 3 times and Hospital Gelderse Vallei (Ede, The Netherlands) once. During the controlled dietary intervention, subjects will visit the Wageningen University 2-3 times a week.

Detailed description

Postprandial glucose responses are related to an increased risk of developing cardiometabolic diseases. Existing research recognizes the presence of inter-individual variation in postprandial glucose responses to the same meal or food product. However, the role of diet, i.e. the other consumed food products and meals, and phenotype in postprandial glucose responses is unclear. A repetitive design and a standardized diet are necessary to determine the variation in postprandial glucose responses to a meal or food product irrespective of the diet. The primary objective of this study is to determine the variation in postprandial glucose responses to the same meals/food products and how this relates to the variation in postprandial glucose responses over a 9-week fully controlled dietary intervention within and between individuals. Our secondary objectives are to investigate the difference between postprandial glucose responses to original products and postprandial glucose responses to reformulated products, and to examine the relation between postprandial glucose responses and short-term well-being. In addition, we aim to study the relation between variation in postprandial glucose and phenotype, including immune function, cognitive performance, and microbiota composition. The study population consists of 63 apparently healthy men and women with a BMI of 25-40 kg/m2, aged 45-75 years, and who are weight stable (± \<3 kg) for at least three months prior to inclusion. The study comprises a characterization period of three weeks, followed by a fully controlled dietary intervention trial of nine weeks. In the characterization period, the phenotype of participants will be determined by measures on anthropometrics, immune function, oxidative stress, advanced glycation end-products, cognitive performance, microbiota and gut health, amylase, genetics, and circulating metabolites. The dietary intervention consists of three repetitive rounds of three weeks, in which we test food products in a cross-over setting. Participants will consume test products that fall in the same food category, but differ in glycaemic index/carbohydrate content. Part of these products is provided by industrial partners, of which the original products are reformulated to be reduced in glycaemic index/carbohydrate content. During the 9-week dietary intervention all foods are provided, giving us a complete and detailed picture of food and nutrient intake during this period. The standardized diet follows the average consumption pattern of the study population. Throughout the intervention, interstitial glucose concentrations will be measured using continuous glucose monitoring (CGM) and physical activity will be monitored with an accelerometer. This study is related to a broad general population. There are minor risks for the research subjects of this study. Placing a continuous glucose sensor generally does not cause pain, but could result in the loss of a drop of blood, or slight skin irritation after wearing. Blood sampling will be performed via a cannula or venapunction and the insertion can be a bit painful and may cause a bruise. During the characterization period, in total 215 mL of blood will be collected in a 3-week timespan. In the following 9 weeks 108 mL, and at the end of the intervention 34 mL blood will be collected. Research subjects will invest approximately 85 hours in the study. During the characterization week, subjects will visit the Wageningen University 3 times and Hospital Gelderse Vallei (Ede, The Netherlands) once. During the controlled dietary intervention, subjects will visit the Wageningen University 2-3 times a week.

Interventions

During 9 weeks all food products will be standardized and provided by the Research Unit. The standardized diet is based on the average food composition in the Netherlands.

Sponsors

Wageningen University
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE

Masking description

Test products will be provided by the care provider/dietician. All others will be blinded during the trial.

Intervention model description

Investigational products will be provided in a standardized environment.

Eligibility

Sex/Gender
ALL
Age
45 Years to 75 Years
Healthy volunteers
Yes

Inclusion criteria

* Apparently healthy men and women * BMI of 25 - 40 kg/m2 * Age 45-75 years * Weight stable (± \<3 kg) for at least two months prior to inclusion

Exclusion criteria

* Diagnosed with type 1 or type 2 diabetes * Diseases or prior surgeries affecting the stomach, liver, or intestines * Food allergies/intolerances for products used in the study design * Receiving medication or supplements interfering with glucose metabolism (as judged by our research physician) * Regular use of medication interfering with immune function (e.g. corticosteroids, immune blockers, as judged by our research physician) * Donated blood within 2 months prior to the screening * Anaemia defined as Hb concentrations \<8.5 mmol/L for men and \<7.5 mmol/L for women * Veins not suitable for venflon needle * Allergy/intolerance to medical skin adhesives * Dietary habits interfering with the study design (e.g. vegetarian, vegan, ketogenic diet) * Intention to change the intensity of exercise during the study period * Current smokers * Alcohol intake ≥14 alcoholic beverages per week (women) or ≥21 alcoholic beverages per week (men) * Being pregnant or lactating * Use of soft and/or hard drugs * Unable/unwilling to download a research application on the mobile phone * Participation in another study that involves an intervention within two months prior to the intervention * Working at the division of Human Nutrition and Health of Wageningen University and Research or the Food, Health and Consumer research group of Wageningen University and Biobased Research

Design outcomes

Primary

MeasureTime frameDescription
Blood glucose profileContinuous for 9 weeksInterstitial glucose concentrations, as measured by continuous glucose monitoring

Secondary

MeasureTime frameDescription
Short-term well-beingBaselineShort-term well-being upon investigational product consumption assessed by the Multidimensional Mood Questionnaire (MDMQ)
Postprandial glucose blood levelsBaselinePostprandial glucose responses in blood upon a mixed meal challenge
Postprandial insulin blood levelsBaselinePostprandial insulin responses in blood upon a mixed meal challenge
Postprandial metabolite blood levelsBaselinePostprandial responses in blood upon a mixed meal challenge as measured by metabolomics
Postprandial gut hormone blood levelsBaselinePostprandial gut hormone concentrations in blood upon a mixed meal challenge
Postprandial lipid profilingBaselinePostprandial lipid profiling in blood upon a mixed meal challenge
Postprandial fatty acid blood levelsBaselinePostprandial fatty acid concentrations in blood upon a mixed meal challenge
Cholesterol concentrationBaselineFasting plasma cholesterol concentration
Postprandial blood glucose levelsBaselinePostprandial glucose responses in blood upon an oral glucose tolerance test
Postprandial blood insulin levelsBaselinePostprandial insulin responses in blood upon an oral glucose tolerance test
Physical activityContinuous for 9 weeksContinuous physical activity levels, measured by the Actigraph accelerometer wGT3X-BT (ActiGraph, Pensacola, USA)
Body fat distributionBaselineRatio between visceral and subcutaneous adipose tissue as measured by magnetic resonance imaging (MRI)
Liver fat contentBaselineLiver fat content as measured by MRS
HbA1cBaselineHbA1c
Fasting glucose concentrationBaselineFasting glucose concentration
Fasting insulin concentrationBaselineFasting insulin concentration
Circulating cytokinesBaselineCirculating plasma cytokines
PBMC compositionBaselineImmune function as measured by PBMC composition
Metabolism immune cell populationsBaselineMetabolism of immune cell populations as measured by SCENITH
Immune functionEnd of intervention (week 12)Metabolism of immune cell populations as measured by SCENITH
Immune responseBaselineImmune response upon TLR stimulation
PBMC cytokine productionBaselinePBMC cytokine production as measured by intracellular staining
Oxidative stress marker urineBaselineOxidative stress as measured by free 8-iso PGF2a in urine
Oxidative stress in plasmaBaselineOxidative stress as measured by MDA levels in plasma
Advanced glycation end-products (AGEs) bloodBaselineAGE concentrations in plasma as measured by ultraperformance liquid chromatography-tandem mass spectrometry
Alpha-dicarbonyl concentrations bloodBaselinealpha-dicarbonyl concentrations in plasma as measured by ultraperformance liquid chromatography-tandem mass spectrometry
AGE accumulationBaselineAccumulation of AGEs in the skin as measured by an AGE reader (Diagnoptics, Groningen, the Netherlands)
Cognitive performanceBaselineCognitive performance as measured by the Cambridge Neuropsychological Test Automated Battery
Oral microbiota compositionBaselineMicrobiota composition in the saliva by extracting bacterial DNA for 16S rRNA sequencing
Fecal microbiota compositionBaselineMicrobiota composition in the feces by extracting bacterial DNA for 16S rRNA sequencing
Self-reported stool consistencyBaselineSelf-reported stool consistency by using the bristol stool chart (scores between 1-7). Low scores indicate constipation and high scores diarrhea. Scores of 3-4 indicate a 'normal' stool.
Transit timeBaselineTransit time, measured as the time in with blue (dietary) dye is consumed and observed in the feces
Salivary amylase concentrationBaselineConcentration of salivary amylase
Salivary amylase activityBaselineActivity of salivary amylase
Genetic variation amylase genesBaselineSNPs in genes coding for amylase, collected using a mouth swab
Genetic variation metabolism and responses to foodBaselineSNPs in genes relevant for metabolism and responses to food, collected using a mouth swab
Habitual dietary intakeBaselineHabitual dietary intake assessment with a food frequency questionnaire (FFQ)
Plasma glucose response fries ABaselinePlasma glucose response to fries type A
Plasma glucose response fries BBaselinePlasma glucose response to fries type B
Plasma glucose response fries CBaselinePlasma glucose response to fries type C
Plasma glucose response yoghurt ABaselinePlasma glucose response to yoghurt type A
Plasma glucose response yoghurt BBaselinePlasma glucose response to yoghurt type B
Plasma glucose response yoghurt CBaselinePlasma glucose response to yoghurt type C
Plasma glucose response cake ABaselinePlasma glucose response to cake type A
Plasma insulin response cake CBaselinePlasma insulin response to cake type C
Plasma glucose response cake BBaselinePlasma glucose response to cake type B
Plasma glucose response cake CBaselinePlasma glucose response to cake type C
Plasma insulin response fries ABaselinePlasma insulin response to fries type A
Plasma insulin response fries BBaselinePlasma insulin response to fries type B
Plasma insulin response cake ABaselinePlasma insulin response to cake type A
Plasma insulin response cake BBaselinePlasma insulin response to cake type B
Plasma insulin response fries CBaselinePlasma insulin response to fries type C
Plasma insulin response yoghurt ABaselinePlasma insulin response to yoghurt type A
Plasma insulin response yoghurt BBaselinePlasma insulin response to yoghurt type B
Plasma insulin response yoghurt CBaselinePlasma insulin response to yoghurt type C

Other

MeasureTime frameDescription
Waist-to-hip ratioBaselineWaist-to-hip ratio
Body mass indexBaselineBody mass index

Countries

Netherlands

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 7, 2026