Clinical trial NCT04298645: Nutrition Trial on the Glycaemic Response to High GI Meals Consumed at Morning vs. Evening-The ChroNu Study
Official 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
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Healthy
Keywords: chronotype
social jetlag
glycaemic response
glycaemic index
continuous glucose monitoring
body composition
Lead sponsor: Paderborn University
Sponsor class: OTHER
Collaborators: name: German Research Foundation
name: German Diabetes Center
name: University of Bergen
First posted: 2020-03-06
Enrollment: 60
Sex: ALL
Minimum age (years): 18
Maximum age (years): 25
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: 60 participants will be invited of which 20 participants with an earlier and 20 participants with a later chronotype are expected to finish the study. Participants will consume a meal rich in carbohydrates with a high GI on two separate days at different times. Hence, participants are randomly assigned to one group stratified by chronotype: intake of a meal with a high GI on day 5 either in the morning or in the evening. On day 7, meal timing of the high GI meal is switched. Following a 3 - day observational part on "free days", the controlled nutrition trial will last 4 days: run - in (day 4), high GI meal for breakfast/dinner (days 5 / 7), and wash - out (day 6). The trial is a two-arm cross-over study in which each participant serves as his / her own control to account for inter-individual variations in diurnal glycaemic responses.
Primary purpose: BASIC_SCIENCE

Brief summary: 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.

Detailed description: 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.

Eligibility criteria: 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

Primary outcomes:
measure: 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).
timeFrame: 2 hour postprandial after test meals
measure: 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).
timeFrame: 2 hours postprandial after test meals
Secondary outcomes:
measure: Diurnal differences in the glycaemic response (iAUC) and in response to the high GI carbohydrates for dinner and the high GI carbohydrates for breakfast.
timeFrame: 24 hours after test meals
measure: Diurnal differences in the glycaemic variability (MAGE) in response to the high GI carbohydrates for dinner and the high GI carbohydrates for breakfast.
timeFrame: 24 hours after test meals
Other outcomes:
measure: Blood lipids, inflammation marker, and glucose homeostasis
timeFrame: 7:30 on run-in day
measure: Insulin level
timeFrame: 7:30 run-in day
measure: Liver enzymes
timeFrame: 7:30 run-in day
measure: Clock gene expression
timeFrame: 7:30 run-in day
measure: Sleep timing
timeFrame: 8 days
measure: Change in fat mass
timeFrame: at baseline (day 1) and after intervention (day 8)
measure: Change in Body Mass Index
timeFrame: at baseline (day 1) and after intervention (day 8)
Locations:
city: Paderborn
country: Germany
facility: Paderborn University
state: North-Rhine Westphalia
Study officials:
affiliation: Paderborn University
name: Anette E Buyken, Prof. Dr.
role: PRINCIPAL_INVESTIGATOR
References: