Effects of Time-Restricted Fasting on the Postprandial Glycemic Responses
- Conditions
- Healthy
- Interventions
- Behavioral: Consumption of breakfast and lunch, with no dinnerBehavioral: Consumption of lunch and dinner, with no breakfast
- Registration Number
- NCT05913635
- Lead Sponsor
- Fudan University
- 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).
Recruitment & Eligibility
- Status
- ACTIVE_NOT_RECRUITING
- Sex
- All
- Target Recruitment
- 36
- Both men and women are eligible.
- Age: 18-40 years old.
- Healthy adults: no history of diabetes mellitus, no use of hypoglycemic drugs, no insulin injection.
- All participants have a good sleep circle, with no somnipathy.
- Severe mental illness or other major medical comorbidities and autoimmune diseases (e.g., chronic renal failure, cardiovascular diseases, or cancer)
- Skipping breakfast or dinner more than 10 times within 6 months.
- Following a special diet, currently on weight loss medication, using sleeping medications.
- Pregnancy or to be pregnant.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description No-dinner Consumption of breakfast and lunch, with no dinner One-day meal plan with no dinner. The dietary plan has been developed according to the Dietary Guidelines for Chinese Residents (2022), and the energy distribution of the two meals (breakfast and lunch) is 1:1, with the energy percentage of carbohydrates, proteins, and fats being 55%, 15%, and 30%, respectively. The total daily calorie intake has been calculated based on the gender difference of the participants. Since the recommended daily calorie intake for males is 2000 kcal while for females it is 1600 kcal, each meal for males is designed to provide 667 kcal calories, comprising 92g carbohydrates, 22g fat, and 25g protein; each meal for females is designed to provide 533 kcal calories, comprising 73g carbohydrates, 18g fat, and 20g protein. The carbohydrates are sourced from buckwheat flour and mixed grain rice, which create similar glycemic indexes for each meal. Additionally, the one-day meal for both males and females includes 450g of vegetables and 320g of fruits. No-breakfast Consumption of lunch and dinner, with no breakfast One-day meal plan with no breakfast. The dietary plan has been developed according to the Dietary Guidelines for Chinese Residents (2022), and the energy distribution of the two meals (lunch and dinner) is 1:1, with the energy percentage of carbohydrates, proteins, and fats being 55%, 15%, and 30%, respectively. The total daily calorie intake has been calculated based on the gender difference of the participants. Since the recommended daily calorie intake for males is 2000 kcal while for females it is 1600 kcal, each meal for males is designed to provide 667 kcal calories, comprising 92g carbohydrates, 22g fat, and 25g protein; each meal for females is designed to provide 533 kcal calories, comprising 73g carbohydrates, 18g fat, and 20g protein. The carbohydrates are sourced from buckwheat flour and mixed grain rice, which create similar glycemic indexes for each meal. Additionally, the one-day meal for both males and females includes 450g of vegetables and 320g of fruits.
- Primary Outcome Measures
Name Time Method 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.
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.
- Secondary Outcome Measures
Name Time Method 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.
Trial Locations
- Locations (1)
Shanghai Institute of Planned Parenthood Research Hospital
🇨🇳Shanghai, Shanghai, China