Effects of Time-Restricted Fasting on the Postprandial Glycemic Responses

Effects of Time-Restricted Fasting on the Postprandial Glycemic Responses in Chinese Adults: A Randomized Crossover Study

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.

Study Overview

• Status: Active, not recruiting
• Conditions: Healthy
• Intervention / Treatment: Behavioral: Consumption of lunch and dinner, with no breakfast; Behavioral: Consumption of breakfast and lunch, with no dinner

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).

• Study Type: Interventional
• Enrollment (Actual): 36
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Shanghai
    • Shanghai, Shanghai, China, 200032
      • Shanghai Institute of Planned Parenthood Research Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 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.	Behavioral: Consumption 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.
Experimental: 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.	Behavioral: Consumption 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from fasting to postprandial postprandial blood glucose	The primary endpoint is fasting and postprandial blood glucose with hexokinase tests.	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
Change from fasting to postprandial insulin	Fasting and postprandial insulin will be tested by ELISA KIT.	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
Results of continuous glucose monitoring	Continuous glucose will be monitored by Abott glucose monitor.	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)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from fasting to postprandial blood lipids	Fasting and postprandial total-, HDL-, LDL-cholesterol, triglyceride will be tested.	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
Analyzes of clock gene expression in peripheral blood cells (PBC)	Clock gene expression in PBC will be evaluated by RT-PCR.	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
Analyzes of postprandial plasma metabolome	Non-targeted plasma metabolites will be tested by LC-MS-MS after 2 hours of each meal.	Blood samples collected at 2 hours after each meal

Collaborators and Investigators

• Sponsor: Fudan University
• Investigators: Principal Investigator: Yuwei Liu, PhD, Fudan University

Publications and helpful links

General Publications

• Nas A, Mirza N, Hagele F, Kahlhofer J, Keller J, Rising R, Kufer TA, Bosy-Westphal A. Impact of breakfast skipping compared with dinner skipping on regulation of energy balance and metabolic risk. Am J Clin Nutr. 2017 Jun;105(6):1351-1361. doi: 10.3945/ajcn.116.151332. Epub 2017 May 10.
• Jakubowicz D, Wainstein J, Landau Z, Raz I, Ahren B, Chapnik N, Ganz T, Menaged M, Barnea M, Bar-Dayan Y, Froy O. Influences of Breakfast on Clock Gene Expression and Postprandial Glycemia in Healthy Individuals and Individuals With Diabetes: A Randomized Clinical Trial. Diabetes Care. 2017 Nov;40(11):1573-1579. doi: 10.2337/dc16-2753. Epub 2017 Aug 22.
• Ogata H, Kayaba M, Tanaka Y, Yajima K, Iwayama K, Ando A, Park I, Kiyono K, Omi N, Satoh M, Tokuyama K. Effect of skipping breakfast for 6 days on energy metabolism and diurnal rhythm of blood glucose in young healthy Japanese males. Am J Clin Nutr. 2019 Jul 1;110(1):41-52. doi: 10.1093/ajcn/nqy346.
• Garaulet M, Lopez-Minguez J, Dashti HS, Vetter C, Hernandez-Martinez AM, Perez-Ayala M, Baraza JC, Wang W, Florez JC, Scheer FAJL, Saxena R. Interplay of Dinner Timing and MTNR1B Type 2 Diabetes Risk Variant on Glucose Tolerance and Insulin Secretion: A Randomized Crossover Trial. Diabetes Care. 2022 Mar 1;45(3):512-519. doi: 10.2337/dc21-1314.
• Lopez-Minguez J, Saxena R, Bandin C, Scheer FA, Garaulet M. Late dinner impairs glucose tolerance in MTNR1B risk allele carriers: A randomized, cross-over study. Clin Nutr. 2018 Aug;37(4):1133-1140. doi: 10.1016/j.clnu.2017.04.003. Epub 2017 Apr 10.

Helpful Links

• Impact of breakfast skipping compared with dinner skipping on regulation of energy balance and metabolic risk
• Influences of Breakfast on Clock Gene Expression and Postprandial Glycemia in Healthy Individuals and Individuals With Diabetes: A Randomized Clinical Trial
• Effect of skipping breakfast for 6 days on energy metabolism and diurnal rhythm of blood glucose in young healthy Japanese males
• Interplay of Dinner Timing and MTNR1B Type 2 Diabetes Risk Variant on Glucose Tolerance and Insulin Secretion: A Randomized Crossover Trial.
• Late dinner impairs glucose tolerance in MTNR1B risk allele carriers: A randomized, cross-over study.

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2022
• Primary Completion (Actual): December 25, 2022
• Study Completion (Estimated): December 31, 2023

Study Registration Dates

• First Submitted: June 11, 2023
• First Submitted That Met QC Criteria: June 21, 2023
• First Posted (Actual): June 22, 2023

Study Record Updates

• Last Update Posted (Actual): June 22, 2023
• Last Update Submitted That Met QC Criteria: June 21, 2023
• Last Verified: June 1, 2023

More Information

Terms related to this study

• Keywords: Continuous Glucose Monitoring; Crossover trial; Postprandial Blood Glucose; Time-Restricted Fasting
• Other Study ID Numbers: 21PJD005

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No