Mechanisms of the Effect of Physical Activity on the Adaptation to a High-Fat Diet
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Healthy
- Sponsor
- Pennington Biomedical Research Center
- Enrollment
- 17
- Locations
- 1
- Primary Endpoint
- To determine the effects of a high fat diet [at both low and high physical activity] on • Sk muscle PGC1α and PDK4 mRNA and protein • Glucose oxidation • Fatty acid oxidation • Hepatic and skeletal muscle lipid • VO2 max • Mitochondr
- Status
- Completed
- Last Updated
- 3 years ago
Overview
Brief Summary
The study is designed to determine the effect of high physical activity level vs. low physical activity level on the adaptation to a high fat diet.
Detailed Description
A high fat diet is linked to weight gain and obesity. An adjustment to the acute exposure to high fat diet is not abrupt and takes time. In a previous study from our laboratory, it has been shown that high level of physical activity can accelerate the adaptation to a high fat diet by increasing fat oxidation. In this study we will determine the mechanism involved in this adjustment. Our hypotheses are: 1. High fat diets decrease skeletal muscle glucose metabolism and decrease mitochondrial biogenesis through the upregulation of PDK4 and downregulation of PGC1α; increased physical activity will prevent these deleterious effects. 2. A high fat diet will increase hepatic and skeletal muscle lipid; increased physical activity will prevent these deleterious effects. 3. These effects are more pronounced in individuals with a low mitochondrial content
Investigators
Eligibility Criteria
Inclusion Criteria
- •Both genders and all races will be invited to participate
- •BMI \> 19 and \< 35 kg/m2
- •Age 18-35
- •Women will be asked to participate in the follicular phase of the menstrual cycle as determined by menstrual history and a negative pregnancy test will be recorded prior to participation
- •Willing and able to walk on a treadmill at a pace of 3 mph at 3%grade for 3-4 hours/day for 3 consecutive days
- •Willing to eat only and all foods provided by Pennington for 9 days on 2 occasions (18 days)
- •Willing to stop alcohol consumption for the duration of the study
- •Able come to Pennington for meals and tests for 20 days 12 of these inpatient.
Exclusion Criteria
- •Significant renal, hepatic, endocrine, pulmonary, cardiac or hematological disease (for the consent form you will have to use kidney, liver, etc )
- •You abuse alcohol or illegal drugs or are unable to avoid alcohol or caffeine prior to testing
- •Unable or unlikely to eat all and only food provided by the PBRC metabolic kitchen.
- •Pregnant or planning to become pregnant
- •Corticosteroid use in previous two months
- •Chronic use of anti-diabetic, anti-hypertensive, or other medications known to affect fat metabolism
- •Use of Depo-Provera, hormone implants or estrogen replacement therapy
- •Irregular menstrual cycles
- •Post-menopausal women
- •Weight gain or loss of \> 3kg in the last 6 months
Outcomes
Primary Outcomes
To determine the effects of a high fat diet [at both low and high physical activity] on • Sk muscle PGC1α and PDK4 mRNA and protein • Glucose oxidation • Fatty acid oxidation • Hepatic and skeletal muscle lipid • VO2 max • Mitochondr
Time Frame: One Year