Recruiting

Time-Restricted Eating

Sponsor:

University of Toronto

Code:

NCT06118931

Conditions

Diabetes Mellitus, Type 2

Obesity

Prediabetic State

Hyperglycemia

Eligibility Criteria

Sex: All

Age: 40+

Healthy Volunteers: Not accepted

Interventions

Early (7:00 - 16:00) TRE

Mid (9:30 - 18:30) TRE

Late (12:00 - 21:00) TRE

Study Details

Brief summary:

This study will evaluate the effectiveness of time-restricted eating (TRE), which is a form of intermittent fasting. When performing TRE, individuals consume all of their calories within a specific time window and then only consume water or other no calorie drinks the rest of the day. TRE is performed each day. There is no restriction on the quality or amount of food that people can consume during their eating window (ad libitum eating) with TRE, which can last anywhere from 4 to 12 hours. We are comparing three different 9-hour eating windows to determine whether the start and stop time of the eating window impact blood sugar control in individuals with obesity who also have or are at risk for type 2 diabetes. We also aim to determine if there are differences in the effects of the timing of eating window between males and females.

Conditions

Diabetes Mellitus, Type 2

Obesity

Prediabetic State

Hyperglycemia

Study ID

NCT06118931

Start date

Jun 28, 2025

Status verified date

Sep, 2025

Completion date

Jun 28, 2027

Anticipated

Primary completion date

Jun 28, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 40+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Aged 40 years or older
  • Body mass index <50 kg/m2
  • Have access to an Apple or Android cellphone with Bluetooth.
  • Have type 2 diabetes or be at risk for type 2 diabetes (defined as self-report of pre-diabetes, a recent (within 12 months) measure of HbA1c between 5.7 and 6.4%, waist circumference (WC) that is BMI specific; for women: BMI >= 18.5-24.9, WC >= 80cm; BMI >= 25-29.9, WC >= 90cm; BMI >= 30-34.9, WC >= 105cm; BMI >= 35+, WC >= 115cm; for men: BMI >= 18.5-24.9, WC >= 90cm; BMI >= 25-29.9, WC >= 100cm; BMI >= 30-34.9, WC >= 110cm; BMI >= 35+, WC >= 125cm.

Exclusion Criteria:

  • Individuals with type 2 diabetes will be excluded if: (1) currently on >2 monotherapies for diabetes, (2) have had diabetes therapy medication or dosage changes <3 months, (3) self-reported hemoglobin A1c >9.0%, (4) taking exogenous insulin, or (5) taking sulfonylureas
  • The following exclusion criteria applies to all potential participants:

1. History of or referral for bariatric surgery
2. Weight loss >3% in the last 3 months
3. Taking antiobesity (weight loss) medications
4. Body weight >390lbs
5. Diagnosed with severe cognitive disorder that precludes them from giving consent
6. Inability or unwillingness to change their eating window to follow those prescribed in the study
7. Currently consistently eating during <11.5 hour period .
8. Physician-diagnosed eating disorder
9. Having a pacemaker or receiving dialysis.
10. Not having access to a Lifelabs location.

Study Design

Enrollment

123 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Early (7:00-16:00h) TRE

Participants will be asked to eat ad libitum between the hours of 7:00 - 16:00 each day for seven days, and then only drink water or other no calorie beverages for the rest of the day. On the 8th day, they will consume one meal replacement beverage at 7:00 and be instructed to not consume anything else for two hours. After the two hours they will be instructed to return to their normal baseline eating habits.

experimental: Mid (9:30-18:30h) TRE

Participants will be asked to eat ad libitum between the hours of 9:30 - 18:30 each day for seven days, and then only drink water or other no calorie beverages for the rest of the day. On the 8th day, they will consume one meal replacement beverage at 9:30 and be instructed to not consume anything else for two hours. After the two hours they will be instructed to return to their normal baseline eating habits.

experimental: Late (12:00-21:00h) TRE

Participants will be asked to eat ad libitum between the hours of 12:00 - 21:00 each day for seven days, and then only drink water or other no calorie beverages for the rest of the day. On the 8th day, they will consume one meal replacement beverage at 12:00 and be instructed to not consume anything else for two hours. After the two hours they will be instructed to return to their normal baseline eating habits.

no intervention: Control

During the first week of the study, participants will be asked to eat as they normally do, and to not make any changes regarding when they are stopping or starting eating.

Interventions

Early (7:00 - 16:00) TRE

A standardized TRE Protocol where participants eat ad libitum between the hours of 7:00 to 16:00 for 7 days. On the 8th day, they will consume a meal replacement beverage at 7:00, and not consume anything else for two hours.

Mid (9:30 - 18:30) TRE

A standardized TRE Protocol where participants eat ad libitum between the hours of 9:30 to 18:30 for 7 days. On the 8th day, they will consume a meal replacement beverage at 9:30, and not consume anything else for two hours.

Late (12:00 - 21:00) TRE

A standardized TRE Protocol where participants eat ad libitum between the hours of 12:00 to 21:00 for 7 days. On the 8th day, they will consume a meal replacement beverage at 12:00, and not consume anything else for two hours.

Primary outcome measure

  • Average 24-hour glucose total area under the curve (AUC) over 7 days [ Time Frame: 7 days ]

Central Contacts and Locations

Central contacts

Amy A Kirkham, PhD

416-946-4069amy.kirkham@utoronto.ca

Teresita Gormaz Clinical Trial coordinator, MsC

+1-416-946-0036establish.study.kpe@utoronto.ca

Locations

Remote Ontario-wide

Recruiting

Toronto, Ontario, Canada

Principal Investigator:

Amy A Kirkham, PhD

More Information

Sponsor

University of Toronto

Last update posted

Jun 30, 2026

Last verified

Sep, 2025

Keywords

  • Time-restricted eating
  • Type 2 Diabetes
  • Obesity
  • Glycemic Control

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by University of Toronto on 2026-06-30.