NCT06118931

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

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

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 120 (estimated)
• Sponsor: University of Toronto · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

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.

Detailed description

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

• Diabetes Mellitus, Type 2
• Obesity
• Prediabetic State
• Hyperglycemia

Interventions

Type	Name	Description
BEHAVIORAL	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.
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.
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.

Timeline

• Start date: 2025-06-28
• Primary completion: 2027-06-28
• Completion: 2027-06-28
• First posted: 2023-11-07
• Last updated: 2025-10-02

Locations

1 site across 1 country: Canada