The Effect of Time-Restricted Eating in Cardiometabolic Health

Study Overview
=================
Brief Summary
-----------------
Time-restricted eating (TRE) is a dietary manipulation that involves restricting food intake to 6-12 h/day with no energy intake the rest of the day. In rodents, TRE improves metabolic function without caloric restriction, potentially by activating nutrient sensing mechanisms and effects on circadian oscillations. However, an understanding of the effect of TRE on cardiometabolic health in people is not clear and few studies have evaluated this issue. Accordingly, the investigators propose to conduct a randomized controlled trial in people with obesity and prediabetes to determine the effect of 9 h TRE for 12 weeks, without a change in body weight, on key metabolic outcomes that are risk factors for cardiovascular disease (CVD): 1) multi-organ insulin sensitivity; 2) 24 h metabolic homeostasis and diurnal rhythm; and 3) adipose tissue and skeletal muscle biology. The proposed studies will elucidate the cardiometabolic implications of TRE in people with obesity and prediabetes.

Official Title
-----------------
The Effect of Time-Restricted Eating in Cardiometabolic Health

Conditions
-----------------
Obesity, PreDiabetes

Intervention / Treatment
-----------------
* Behavioral: Time restricted eating
* Behavioral: Extended eating window
* Behavioral: Healthy diet


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: must be able to grant voluntary informed consent and comply with the study instructions aged 25-75 years men and women body mass index 27-45 kg/m2 fasting plasma glucose 5.6-6.9 mmol/L, or 2h oral glucose tolerance test plasma glucose 7.8-11.1 mmol/L or haemoglobin A1C 39-46 mmol/mol or homeostasis model assessment-insulin resistance (HOMA-IR) score ≥2.73 self-reported habitual eating period ≥ 13 h per day Exclusion Criteria: shift worker fasting >12 h/day more than once a week vegan > once a week no food intake after  1800 h habitually waking up before  0400 h and sleeping before  2100 h unstable weight (>5% change the last 2 months) Clinical diagnosis of type 1 or 2 diabetes Clinical diagnosis of sleep disorder Clinical diagnosis of eating disorder Clinical diagnosis of cancer in last 5 years conditions that render subject unable to complete all testing procedures (including individuals with known allergies or contraindications to the medications used in this study) use of medications that affect the study outcome measures or increase the risk of study procedures and that cannot be temporarily discontinued (e.g., steroids, alpha- or beta-adrenergic blockers or agonists, etc.) smoking and illegal drug use pregnant or lactating gastrointestinal or bariatric surgery (except cholecystectomy and appendectomy) individuals with electromedical devises prisoners alcohol abuse

Ages Eligible for Study
-----------------
Minimum Age: 25 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: TRE group<br>Participants assigned to the TRE group will have to consume all their daily meals and snacks during a 9-hour window for 12 weeks. | Behavioral: Time restricted eating<br>* Participants assigned to the TRE group will have to consume all their daily meals and snacks during a 9-hour window for 12 weeks.<br>Behavioral: Healthy diet<br>* Participants will be provided nutrition education and counselling to follow a diet consistent with the existing guidelines for chronic disease prevention.<br>|
| Active Comparator: Control group<br>Participants assigned to the control group will have to consume all their daily meals and snacks during a 14-hour window for 12 weeks. | Behavioral: Extended eating window<br>* Participants assigned to the control group will have to consume all their daily meals and snacks during a 14-hour window for 12 weeks.<br>Behavioral: Healthy diet<br>* Participants will be provided nutrition education and counselling to follow a diet consistent with the existing guidelines for chronic disease prevention.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Insulin sensitivity | Insulin sensitivity will be assessed by using a hyperinsulinemic euglycemic clamp procedure in conjunction with infusion of stable isotope tracers. | 3 months (pre-post intervention) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24 h glycemic control | Changes in plasma glucose concentration will be assessed during a 24 h feeding study. | 3 months (pre-post intervention) | 
| Adipose tissue gene expression | Changes in the expression of genes involved in energy metabolism will be assessed by using quantitative polymerase chain reaction (qPCR). | 3 months (pre-post intervention) |