Diet Modification, Physical Activity
Conditions
Brief summary
Prolonged sitting has been shown to impair metabolism and vascular function. The overall purpose of this study is to determine if breaking up prolonged (9 hours) of sitting with brief (\ 20 second) stair climbing exercise snacks can improve markers of metabolic control and vascular health in healthy young male participants and in males or females with overweight/obesity who are at risk of insulin resistance. An additional purpose is to determine if saliva insulin can be used as a valid indicator of blood insulin when measured throughout the day in sedentary and active conditions and when diets with different amounts of carbohydrates are consumed.
Interventions
BEHAVIORALHigh-Carbohydrate Sedentary
Three high-carbohydrate meals will be consumed (breakfast, lunch, and dinner) at \ 3 hour intervals while participants remain in a seated position for the entire 9 hour intervention period.
BEHAVIORALHigh-Carbohydrate Active
Three high-carbohydrate meals will be consumed (breakfast, lunch, and dinner) at \ 3 hour intervals while participants remain in a seated position for the entire 9 hour intervention period except that once every hour they will ascend three flights of stairs vigorously (stair climbing sprint snack) for a total of 8 active breaks.
BEHAVIORALLow-carbohydrate Sedentary
Three low-carbohydrate meals will be consumed (breakfast, lunch, and dinner) at \ 3 hour intervals while participants remain in a seated position for the entire 9 hour intervention period. This condition will provide a condition where the blood glucose and insulin responses are relatively low and stable throughout the day.
Sponsors
Mitacs
CoreHealth Technologies Inc.
University of British Columbia
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
NONE
Masking description
It is not possible to mask the exercise or diet interventions.
Intervention model description
Participants complete three conditions in a repeated crossover design.
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
Lean Group Inclusion Criteria: Non-smoking Lean Group
Exclusion criteria
Diagnosed with diabetes or prediabetes (fasting blood sugar more than 6.0 mmol/l) or any other chronic condition that may impact glucose or insulin levels. BMI is over 25 kg/m2 Take medications which may affect glucose and insulin levels Allergic to eggs. Smoker Competitive or serious endurance athlete. Overweight/Obese Group Inclusion Criteria: Elevated waist circumference (\>102 cm for male and \>88 cm for female) Overweight/Obese Group
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Plasma insulin area under the curve | Measured across 9 hours of each intervention day | The plasma insulin concentration measured by enzyme-linked immunosorbent assay area under the curve will be measured using the trapezoidal rule. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Plasma glucose area under the curve | Measured across 9 hours of each intervention day | The plasma glucose concentration measured by hexokinase method area under the curve will be measured using the trapezoidal rule. |
| Plasma triglyceride area under the curve | Measured across 9 hours of each intervention day | The plasma triglyceride concentration measured by biochemical assay area under the curve will be measured using the trapezoidal rule. |
| Plasma non-esterified fatty acids area under the curve | Measured across 9 hours of each intervention day | The plasma non-esterified fatty acid concentration measured by biochemical assay area under the curve will be measured using the trapezoidal rule. |
| Saliva insulin area under the curve | Measured across 9 hours of each intervention day | The saliva insulin concentration measured by enzyme-linked immunosorbent assay area under the curve will be measured using the trapezoidal rule. |
| Cerebrovascular function | Measured in the morning (time 0.5 hours) and afternoon (time 6 hours) each intervention day | Cerebrovascular function measured by transcranial doppler ultrasound |
| Cognitive function | Measured in the morning (time 0.5 hours) and afternoon (time 6 hours) each intervention day | Cognitive function measured by Computerized Neurocognitive Assessment Software (CNS) Vital Signs test battery |
| Femoral artery flow-mediated dilation | Measured in the morning (time 0 hours) and afternoon (time 8.5 hours) each intervention day | Flow-mediated dilation of femoral artery measured by vascular ultrasound |
Countries
Canada
Outcome results
None listed