Obesity; Endocrine
Conditions
Keywords
Exercise, Diet, Overweight, Glycaemic control, Fitness, Body composition
Brief summary
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
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.
Interventions
BEHAVIORALHigh Intensity Interval Training
Three weekly, supervised exercise sessions with high intensity. Each session will last for 30-45 minutes. Intervention period will be seven weeks.
BEHAVIORALTime-Restricted Eating
Restricted daily window of caloric intake to maximum 10 hours. Intervention period will be seven weeks.
Sponsors
Norwegian University of Science and Technology
Australian Catholic University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
Four-armed randomised controlled trial
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 45 Years
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Glycaemic control | From baseline to after 7 weeks intervention | Total area under the plasma glucose curve over two hours after a 75 g oral glucose tolerance test |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Insulin sensitivity | From baseline to after 7 weeks intervention | 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) |
| Insulin levels after ingestion of glucose | From baseline to after 7 weeks intervention | Total area under the serum insulin two hours after a 75 g oral glucose tolerance test |
| Cardiorespiratory fitness | From baseline to after 7 weeks intervention | Peak oxygen uptake at a maximum effort exercise test, measured in mL/min/kg and L/min |
| Body mass | From baseline to after 7 weeks intervention | In kg |
| Body fat mass | From baseline to after 7 weeks intervention | In kg |
| Body fat percentage | From baseline to after 7 weeks intervention | In percent of total body mass |
| Fat-free body mass | From baseline to after 7 weeks intervention | In kg |
| Fat-free body mass percentage | From baseline to after 7 weeks intervention | In percent of total body mass |
| Systolic blood pressure | From baseline to after 7 weeks intervention | Average of three measurements, in mmHg |
| Diastolic blood pressure | From baseline to after 7 weeks intervention | Average of three measurements, in mmHg |
| Resting heart rate | From baseline to after 7 weeks intervention | Average of three measurements, in beats/min |
| Cholesterol in blood | From baseline to after 7 weeks intervention | Total fasting cholesterol in blood |
| High density lipoprotein cholesterol in blood | From baseline to after 7 weeks intervention | Fasting high density lipoprotein cholesterol i blood |
| Low density lipoprotein cholesterol in blood | From baseline to after 7 weeks intervention | Fasting low density lipoprotein cholesterol i blood |
| Triglycerides in blood | From baseline to after 7 weeks intervention | Fasting low density lipoprotein cholesterol i blood |
| Average glucose levels | From baseline to after 7 weeks intervention | Glycated haemoglobin (HbA1c) |
| Insulinemia | From baseline to after 7 weeks intervention | Fasting insulin in blood |
| 24 hour glycaemic control | From baseline to the last 14 days of the intervention period | Average interstitial glucose levels during 24 h, area under the curve |
| Postprandial glycaemic control | From baseline to the last 14 days of the intervention period | Average interstitial glucose levels 3 hours after the first meal of the day, area under the curve |
| Nocturnal glycaemic control | From baseline to the last 14 days of the intervention period | Average interstitial glucose levels from 23:00 h to 06:00 h |
| Self-reported physical activity | From baseline to after 7 weeks intervention | International Physical Activity Questionnaire |
| Measured physical activity | From baseline to the last 14 days of the intervention period | Measure by Sensewear activity monitor |
| Sleep | From baseline to after 7 weeks intervention | Self-reported: Pittsburgh Sleep Quality Index |
| Chronotype | From baseline to after 7 weeks intervention | Self-reported: Hornestberg Morningness Eveningness Questionnaire |
Countries
Norway
Contacts
STUDY_DIRECTORØystein T Risa, PhD
Norwegian University of Science and Technology
PRINCIPAL_INVESTIGATORTrine T Moholdt, PhD
Norwegian University of Science and Technology
Outcome results
None listed