Time-restricted Eating and High Intensity Interval Training Among Women

Study Overview
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Brief Summary
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This project will determine the independent and combined effects of high intensity interval training and time-restricted eating on blood sugar regulation among women in reproductive-age who have overweight or obesity. The intervention period will be seven weeks. Before and after the intervention, blood sugar regulation, body composition and physical fitness will be measured and compared between groups who are doing either high intensity interval training, time-restricted eating, both high intensity interval training and time-restricted eating, or who are in a control group. Physical activity, sleep quality, continuous glucose monitoring, adherence to the interventions and hunger/satiety will also be measured.

Detailed Description
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In a follow-up study, we will invite randomized participants to come in for new assessments of physical fitness, body composition and fasting blood samples, and they will be asked to complete questionnaires about adherence to the interventions two years after intervention-end. The first participants will come in to the laboratory for the two-year follow up in November 2021.

Official Title
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Isolated and Combined Effects of High Intensity Interval Training and Time Restricted Eating on Glycaemic Control in Reproductive-aged Women With Overweight or Obesity

Conditions
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Obesity; Endocrine

Intervention / Treatment
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* Behavioral: High Intensity Interval Training
* Behavioral: Time-Restricted Eating


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: body mass index ≥ 27 kg/cm2, able to walk on a treadmill or ride a bike for at least 60 min. Exclusion Criteria: Pregnancy, lactation within 24 weeks of study commencement known cardiovascular disease type 1 or 2 diabetes currently taking hypertension or glucose- or lipid-lowering medication habitual eating window < 12 hours performing high intensity training more than once a week body mass variations > 4 kg three months prior to study commencement shift work that includes night shifts.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Four-armed randomised controlled trial
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High Intensity Interval Training<br>High intensity interval training for seven weeks. Three weekly, supervised training sessions. | Behavioral: High Intensity Interval Training<br>* Three weekly, supervised exercise sessions with high intensity. Each session will last for 30-45 minutes. Intervention period will be seven weeks.<br>|
| Experimental: Time-Restricted Eating<br>Time-restricted eating for seven weeks. Maximal daily eating window of 10 hours. | Behavioral: Time-Restricted Eating<br>* Restricted daily window of caloric intake to maximum 10 hours. Intervention period will be seven weeks.<br>|
| Experimental: High Intensity Interval Training & Time-Restricted Eating<br> | Behavioral: High Intensity Interval Training<br>* Three weekly, supervised exercise sessions with high intensity. Each session will last for 30-45 minutes. Intervention period will be seven weeks.<br>Behavioral: Time-Restricted Eating<br>* Restricted daily window of caloric intake to maximum 10 hours. Intervention period will be seven weeks.<br>|
| No Intervention: Control<br>Will be given information about the recommended level of physical activity for health benefits and a healthy diet. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Glycaemic control | Total area under the plasma glucose curve over two hours after a 75 g oral glucose tolerance test | From baseline to after 7 weeks intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Insulin sensitivity | Insulin sensitivity estimated by homeostatic model assessment for insulin resistance (fasting serum insulin concentration (μU/mL) x fasting plasma glucose levels (mmol/L)/22.5) | From baseline to after 7 weeks intervention | 
| Insulin levels after ingestion of glucose | Total area under the serum insulin two hours after a 75 g oral glucose tolerance test | From baseline to after 7 weeks intervention | 
| Cardiorespiratory fitness | Peak oxygen uptake at a maximum effort exercise test, measured in mL/min/kg and L/min | From baseline to after 7 weeks intervention | 
| Body mass | In kg | From baseline to after 7 weeks intervention | 
| Body fat mass | In kg | From baseline to after 7 weeks intervention | 
| Body fat percentage | In percent of total body mass | From baseline to after 7 weeks intervention | 
| Fat-free body mass | In kg | From baseline to after 7 weeks intervention | 
| Fat-free body mass percentage | In percent of total body mass | From baseline to after 7 weeks intervention | 
| Systolic blood pressure | Average of three measurements, in mmHg | From baseline to after 7 weeks intervention | 
| Diastolic blood pressure | Average of three measurements, in mmHg | From baseline to after 7 weeks intervention | 
| Resting heart rate | Average of three measurements, in beats/min | From baseline to after 7 weeks intervention | 
| Cholesterol in blood | Total fasting cholesterol in blood | From baseline to after 7 weeks intervention | 
| High density lipoprotein cholesterol in blood | Fasting high density lipoprotein cholesterol i blood | From baseline to after 7 weeks intervention | 
| Low density lipoprotein cholesterol in blood | Fasting low density lipoprotein cholesterol i blood | From baseline to after 7 weeks intervention | 
| Triglycerides in blood | Fasting low density lipoprotein cholesterol i blood | From baseline to after 7 weeks intervention | 
| Average glucose levels | Glycated haemoglobin (HbA1c) | From baseline to after 7 weeks intervention | 
| Insulinemia | Fasting insulin in blood | From baseline to after 7 weeks intervention | 
| 24 hour glycaemic control | Average interstitial glucose levels during 24 h, area under the curve | From baseline to the last 14 days of the intervention period | 
| Postprandial glycaemic control | Average interstitial glucose levels 3 hours after the first meal of the day, area under the curve | From baseline to the last 14 days of the intervention period | 
| Nocturnal glycaemic control | Average interstitial glucose levels from 23:00 h to 06:00 h | From baseline to the last 14 days of the intervention period | 
| Self-reported physical activity | International Physical Activity Questionnaire | From baseline to after 7 weeks intervention | 
| Measured physical activity | Measure by Sensewear activity monitor | From baseline to the last 14 days of the intervention period | 
| Sleep | Self-reported: Pittsburgh Sleep Quality Index | From baseline to after 7 weeks intervention | 
| Chronotype | Self-reported: Hornestberg Morningness Eveningness Questionnaire | From baseline to after 7 weeks intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Exercise, Diet, Overweight, Glycaemic control, Fitness, Body composition