Healthy
Conditions
Keywords
Time-Restricted Fasting, Postprandial Blood Glucose, Continuous Glucose Monitoring, Crossover trial
Brief summary
The goal of this clinical trial is to investigate whether fasting timing has a significant effect on postprandial glycemic responses in healthy adults. The main questions it aims to answer are: 1. Whether fasting timing has a significant effect on postprandial insulin actions and plasma glucose concentration. 2. Whether fasting timing could modulate the glycemic metabolome and circadian rhythms in healthy individuals. Participants will get the two interventions: No-dinner: breakfast at 7.30 a.m., lunch at 1.00 p.m. and no dinner; No-breakfast: no breakfast, lunch at 1.00 p.m. and dinner at 8.00 p.m.
Detailed description
A randomized, crossover study design is used with 2 intervention days and a 6-day washout period, to evaluate the effects of early and late fasting on postprandial glucose responses in healthy adults. Randomization was performed by the Fudan staff with a block size of 2 using a balanced design using computer-executed software. The primary endpoint is the fasting and postprandial blood glucose, insulin, and continuous glucose monitoring after fasting. Secondary endpoints include postprandial blood lipids, clock gene expressions in peripheral blood cells, and non-targeted postprandial plasma metabolome. The 2 intervention days include a no-breakfast day and a no-dinner day. The diets before, during, and after the intervention day was designed according to Dietary Guidelines for Chinese Residents (2022), and the energy distribution of three meals is 1:1:1, with the energy percentage of carbohydrate, protein, and fat being 55%, 15%, and 30%, respectively. The time of breakfast, lunch, and dinner is 7.30 a.m., 1.00 p.m., and 8.00 p.m., respectively. All participants are instructed to follow their natural dietary plans in the wash-out period, and the food intakes and sleep circle were recorded by a modified food frequency questionnaire (FFQ).
Interventions
BEHAVIORALConsumption of lunch and dinner, with no breakfast
The day before intervention day, all participants will be provided with 3 nutritionally balanced meals which are designed by the investigators. On the no-breakfast intervention day, participants are instructed to fast and only be allowed to consume water until 1.00 p.m. and consume the above-designed lunch and dinner at 1.00 p.m. and 8.00 p.m. Additionally, all participants are informed that they are only allowed to consume water between meals and before receiving breakfast at 7.30 a.m. the following day.
BEHAVIORALConsumption of breakfast and lunch, with no dinner
The day before intervention day, all participants will be provided with 3 nutritionally balanced meals which are designed by the investigators. On the no-dinner intervention day, participants are instructed to consume the above-designed breakfast and lunch at 7.30 a.m. and 1.00 p.m., and no dinner. Additionally, all participants are informed that they are only allowed to consume water between meals and before receiving breakfast at 7.30 a.m. on the following day.
Sponsors
Fudan University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)
Masking description
The researchers who conducted the biomarker measurements were not aware of the assignments of the trial.
Intervention model description
A randomized, crossover study design uses two intervention days (a no-breakfast day and a no-dinner day) and a 6-day washout period.
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
1. Both men and women are eligible. 2. Age: 18-40 years old. 3. Healthy adults: no history of diabetes mellitus, no use of hypoglycemic drugs, no insulin injection. 4. All participants have a good sleep circle, with no somnipathy.
Exclusion criteria
1. Severe mental illness or other major medical comorbidities and autoimmune diseases (e.g., chronic renal failure, cardiovascular diseases, or cancer) 2. Skipping breakfast or dinner more than 10 times within 6 months. 3. Following a special diet, currently on weight loss medication, using sleeping medications. 4. Pregnancy or to be pregnant.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Results of continuous glucose monitoring | From the day before the first intervention day and the wash-out period till the day after the second intervention day (10 days in total) | Continuous glucose will be monitored by Abott glucose monitor. |
| Change from fasting to postprandial postprandial blood glucose | Blood samples collected before and after 2 hours at lunch on the no-breakfast day; blood samples collected before and after 2 hours at next day breakfast on the no-dinner day | The primary endpoint is fasting and postprandial blood glucose with hexokinase tests. |
| Change from fasting to postprandial insulin | Blood samples collected before and after 2 hours at lunch on the no-breakfast day; blood samples collected before and after 2 hours at next day breakfast on the no-dinner day | Fasting and postprandial insulin will be tested by ELISA KIT. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change from fasting to postprandial blood lipids | Blood samples collected before and after 2 hours at lunch on the no-breakfast day; blood samples collected before and after 2 hours at next day breakfast on the no-dinner day | Fasting and postprandial total-, HDL-, LDL-cholesterol, triglyceride will be tested. |
| Analyzes of clock gene expression in peripheral blood cells (PBC) | PBC samples collected before and after 2 hours at lunch on the no-breakfast day; blood samples collected before and after 2 hours at next day breakfast on the no-dinner day | Clock gene expression in PBC will be evaluated by RT-PCR. |
| Analyzes of postprandial plasma metabolome | Blood samples collected at 2 hours after each meal | Non-targeted plasma metabolites will be tested by LC-MS-MS after 2 hours of each meal. |
Countries
China
Outcome results
None listed