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Completed

NCT Number: NCT04298645

Nutrition Trial on the Glycaemic Response to High GI Meals Consumed at Morning vs. Evening-The ChroNu Study

Several studies suggest that meal timing plays an important role in the development of obesity and metabolic diseases. Especially in the evening, a high consumption of carbohydrates, which greatly increase blood glucose levels (i.e. unfavourable carbohydrates with a higher glycaemic index (GI)), has been found to adversely affect glycaemic response. However, avoidance of (unfavourable) carbohydrate consumption appears to be particularly problematic for young adults due to its interference with the timing of social life and their chronotype. The chronotype describes individual differences in sleep timing on free days and is most delayed around the age of 20. Young adults are thus prone to be exposed to a dietary misalignment when socially determined schedules, such as early lectures at universities, collide with their biologically determined later chronotype.

Therefore, it is hypothesized that dietary misalignment among young adults has detrimental short-term effects on the glucose metabolism.

In this nutrition trial, dietary misalignment is induced by providing the same meal rich in carbohydrates with a high glycaemic index (GI) on two separate days at different times: breakfast at 7:00 is assumed to reflect a schedule potentially inducing dietary misalignment among later chronotypes. Vice versa, providing this meal at dinner (20:00) may cause dietary misalignment among earlier chronotypes.

Adverse glycaemic responses are expected when the high GI meal is consumed at a time which is deviating from the schedule of the individual chronotype. A regular increase in postprandial glycaemia due to constant dietary misalignment may be important in the development of metabolic diseases.

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Key information

Conditions

Healthy

Age range

18 year–25 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Paderborn University

Paderborn, North Rhine-Westphalia, 33098, Germany

About this study

To address the hypothesis that dietary misalignment among young adults has detrimental short-term effects on glucose metabolism, participants will consume a meal rich in high GI carbohydrates on two separate days either at breakfast (7:00) or at dinner (20:00). Glycaemic responses will be monitored by a continuous glucose monitoring device (CGM) (G6, Dexcom, Inc., San Diego, CA). The CGM electrochemically measures subcutaneous interstitial glucose concentrations of each participant during the whole study. A blood glucose meter will be used to verify the functionality of the CGM (CONTOUR®NEXT ONE).

The caloric content of the meals will be tailored to the energy needs of the participants based on their age, sex and anthropometric measurements. Participants will be requested to consume the meals without any break. During the controlled nutrition trial, participants will be asked to abstain from alcohol consumption and heavy exercise and not consume any food in addition to that provided or drinks that should be explicitly avoided.

To objectively corroborate their chronotype participants will be asked to wear an accelerometer (E4 wristband, Empatica) attached to the wrist during the controlled nutrition trial. Moreover, participants are asked to record their bed times, meal timings, daily routines, and physical activities during the trial. On day 1 and day 8, anthropometric measurements will be performed to compare the body composition (Bioimpedance Analysis, SECA mBCA) before and after the controlled nutrition trial. On day 4, fasting blood samples will be collected. Before the controlled nutrition trial will start, questionnaires on daily routines, food frequency, and chronotype will be carried out.

The chronotype is defined as mid-sleep point and assessed by the Munich Chronotype Questionnaire, which is a validated questionnaire. Earlier and later chronotypes will be defined as 20% of the participants with each the earliest and later mid-sleep points among the participants of the ChroNu cohort.

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • Healthy students of Paderborn University
  • 18 - 25 years old at time of screening for the ChroNu cohort
  • 18,5 kg/m² < BMI > 30 kg/m²
  • Free of diseases requiring constant or chronic medical treatment (except for oral contraceptives)
  • Willingness to participate in the nutrition trial (8 days) including invasive measurements
  • Fluent knowledge of the German language

Exclusion criteria

  • students studying nutrition science at the University Paderborn
  • regular smokers
  • pregnancy or lactation
  • chronic diseases: diabetes mellitus (all types), pre-diabetes, individuals with bleeding disorders (thrombocytopenia, haemophilia)
  • contact dermatitis to adhesive plaster or skin disease that prevents the participant from wearing the CGM
  • intake of medication which influence the chronotype: such as antidepressants or sleeping pills
  • shift work in the past 3 months
  • crossing of > 1-time zone in the past 3 months
  • strict vegetarians /vegans
  • individuals having an allergy or intolerance to food that is included in the diet

Treatment and study plan

Glycaemic response to high GI carbohydrates consumed at morning versus evening meals.

Other

Controlled nutrition trial on the glycaemic response to morning and evening meals with high glycemic index carbohydrates among students with early and late chronotypes.

Primary outcomes

  1. Differences in the 2-h pp glycaemic response between the high GI carbohydrate meal consumed for breakfast (7:00) and the high GI carbohydrate meal consumed for dinner (20:00).

    Time frame: 2 hour postprandial after test meals

    2 hour post prandial response (iAUC) is calculated as the incremental area under the curve of measurements taken within the two hours after the test meals.

  2. Differences in the 2-h pp glycaemic variability between the high GI carbohydrate meal consumed for breakfast (7:00) and the high GI carbohydrate meal consumed for dinner (20:00).

    Time frame: 2 hours postprandial after test meals

    the 2-h pp glycaemic variability (MAGE) is calculated as the mean amplitude of glycaemic excursions during the two hours after the test meals, i.e. both resemble summary measures calculated from repeated measurements taken the 2 h pp.

Secondary outcomes

  1. Diurnal differences in the glycaemic response (iAUC) and in response to the high GI carbohydrates for dinner and the high GI carbohydrates for breakfast.

    Time frame: 24 hours after test meals

    24 hour post prandial response (iAUC) is calculated as the incremental area under the curve of measurements taken within the 24 hours after the test meals.

  2. Diurnal differences in the glycaemic variability (MAGE) in response to the high GI carbohydrates for dinner and the high GI carbohydrates for breakfast.

    Time frame: 24 hours after test meals

    24-h pp glycaemic variability (MAGE) is calculated as the mean amplitude of glycaemic excursions during the 24 hours after the test meals, i.e. both resemble summary measures calculated from repeated measurements taken the 24 h pp.

Other outcomes

  1. Blood lipids, inflammation marker, and glucose homeostasis

    Time frame: 7:30 on run-in day

    Blood lipids, markers of chronic inflammation, and glucose homeostasis will be measured from serum or plasma obtained from fasting whole blood samples.

    • total cholesterol (mmol/L)
    • triglycerides (mmol/L)
    • LDL- cholesterol (mmol/L)
    • HDL- cholesterol (mmol/L
    • small-dense LDL (mmol/L)
    • small-dense HDL (mmol/L)
    • high-sensitivity C-reactive protein (mmol/L)
    • Fasting blood glucose (mmol/L)

  2. Insulin level

    Time frame: 7:30 run-in day

    • fasting plasma insulin level (µE/mL)

  3. Liver enzymes

    Time frame: 7:30 run-in day

    • Alanine transaminase (U/L)
    • γ- Glutamyltransferase (U/L)

  4. Clock gene expression

    Time frame: 7:30 run-in day

  5. Sleep timing

    Time frame: 8 days

    Sleep timing (unit) will be determined using an accelerometer (Empatica E4) and manually kept diary during the 8 days of nutrition trial. This information will serve to to corroborate the chronotype of the participants.

  6. Change in fat mass

    Time frame: at baseline (day 1) and after intervention (day 8)

    Body composition is electronically analyzed using Bioimpedance Analysis (BIA) (mBCA 515, SECA).

  7. Change in Body Mass Index

    Time frame: at baseline (day 1) and after intervention (day 8)

    Body Mass Index (BMI) is calculated by weight(kg) / height(m)²). Weight and height are measured electronically.

Sponsors and collaborators

Lead sponsor

Paderborn University

Other

Collaborators

  • German Diabetes Center
  • German Research Foundation
  • University of Bergen

Registry information

Official study title

Controlled Nutrition Trial on the Glycaemic Response to Morning and Evening Meals With High Glycemic Index Carbohydrates Among Students With Early and Late Chronotypes-The ChroNu Study

Acronym: ChroNu

Important dates

Study start
2020
Primary completion
2020
Study completion
2020
First posted
Mar 6, 2020
Registry last updated
Dec 23, 2020

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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