Time-restricted Eating, Window Timing, Type 2 Diabetes Status and Sex on Glycemic Control

NCT ID: NCT06118931

Last Updated: 2025-10-02

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

120 participants

Study Classification

INTERVENTIONAL

Study Start Date

2025-06-28

Study Completion Date

2027-06-28

Brief Summary

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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.

Detailed Description

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The overarching aim of this study is to evaluate the interactions between TRE window timing, type 2 diabetes status, and sex among individuals with obesity. The first objective is to compare the effects of three 9-h TRE window times (early: 7:00-16:00 h, mid: 9:30-18:30 h, delayed: 12:00-21:00 h) on real-time, free-living glycemic control. The second objective is to determine if type 2 diabetes status (type 2 diabetes versus prediabetes or moderate+ risk for type 2 diabetes aka at risk for type 2 diabetes) modifies the effect of eating window timing on glycemic control outcomes. The exploratory objectives include: 1) determine whether sex modifies TRE adherence or the effect of TRE on metabolic changes relative to control; and 2) to compare changes in dietary intake, body weight, and blood pressure within and between early, mid, and delayed TRE. We have the following hypotheses related to these objectives:

1. The early TRE window will result in the most favourable glycemic control outcomes but also the lowest participant acceptability followed by mid and delayed TRE.
2. There will be larger differences in glycemic control outcomes between the TRE window timings among those with type 2 diabetes compared to those at risk for type 2 diabetes.
3. TRE adherence and changes in glycemic control, and weight loss with all TRE window times (relative to control) will be higher in men vs women.
4. Energy, carbohydrate, and sugar intake, body weight, and blood pressure will decrease during TRE, but with no differences by window timing.

Conditions

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Diabetes Mellitus, Type 2 Obesity Prediabetic State Hyperglycemia

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

CROSSOVER

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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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.

Group Type EXPERIMENTAL

Early (7:00 - 16:00) TRE

Intervention Type BEHAVIORAL

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 (9:30-18:30h) 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.

Group Type EXPERIMENTAL

Mid (9:30 - 18:30) TRE

Intervention Type BEHAVIORAL

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 (12:00-21:00h) 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.

Group Type EXPERIMENTAL

Late (12:00 - 21:00) TRE

Intervention Type BEHAVIORAL

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.

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.

Group Type NO_INTERVENTION

No interventions assigned to this group

Interventions

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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.

Intervention Type BEHAVIORAL

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.

Intervention Type BEHAVIORAL

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.

Intervention Type BEHAVIORAL

Eligibility Criteria

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Inclusion Criteria

* Aged \>18 years
* Body mass index \>30 kg/m2 and \<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 high (33+) Canadian Diabetes Risk Score)

Exclusion Criteria

* Individuals with type 2 diabetes will be excluded if: (1) currently on \>3 monotherapies for diabetes, (2) have had diabetes therapy dosage changes \<3 months, (3) self-reported hemoglobin A1c \>9.0%, (4) taking exogenous insulin, or (5) taking sulfonylureas

1. History of or referral for bariatric surgery
2. Weight loss \>5% in the last 3 months
3. Taking antiobesity (weight loss) medications
4. Body weight \>340lbs
5. Diagnosed 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 eating during \<12 hour period on 5 or more days/week
8. Physician-diagnosed eating disorder
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Diabetes Canada

OTHER

Sponsor Role collaborator

Wharton Medical Clinic

UNKNOWN

Sponsor Role collaborator

University of Toronto

OTHER

Sponsor Role lead

Responsible Party

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Amy Kirkham

Principal Investigator

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Amy A. Kirkham, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Toronto

Locations

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Remote Ontario-wide

Toronto, Ontario, Canada

Site Status RECRUITING

Countries

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Canada

Central Contacts

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Amy A Kirkham, PhD

Role: CONTACT

416-946-4069

Rebecca AG Christensen, PhD

Role: CONTACT

Facility Contacts

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Amy A Kirkham, PhD

Role: primary

Other Identifiers

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44122

Identifier Type: -

Identifier Source: org_study_id

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