Healthy
Conditions
Brief summary
This study is designed to predict weight gain overtime after a high fat diet.
Detailed description
In the past 3 years we have identified a thrifty-phenotype characterized in lean men by an inability to adapt rapidly to a high fat diet and associated with a low maximal VO2 and high fasting insulin. We hypothesize that the individuals with the thrifty phenotype are at higher risk for becoming obese, and that exercise may be effective in overcoming this problem. Several questions remain to be answered regarding the thrifty phenotype. First, given the large interindividual differences, how can we identify those at the highest risk? What are the distinguishing biochemical, endocrine and environmental characteristics of individuals that store fat when exposed to high fat diets? This is important because if these individuals can be easily identified, then dietary interventions can be targeted to this at-risk population. Second, what is different about the individual with the thrifty phenotype? Are there cellular pathways that are dysregulated in the skeletal muscle of these individuals when compared to controls? Is the defect intrinsic, i.e. a diminished ability to conserve glucose and oxidize fat in skeletal muscle or alternately, is the phenotype due to environmental, and dietary factors such as inactivity and energy excess? To answer these questions, we have planned a three-year project that aims to: * Characterize the biochemical, endocrine, anthropometric and environmental characteristics of individuals with the thrifty phenotype. * Identify the signaling pathways in skeletal muscle that are dysregulated in individuals with the thrifty phenotype through mRNA expression profiling in skeletal tissue. * Determine the role of environmental factors such as inactivity and caloric intake vs. intrinsic (genetic) factors in the thrifty phenotype.
Interventions
BEHAVIORALHigh Fat Diet
Daily eating
BEHAVIORALLow Fat Diet
Life style eating habits
Sponsors
Pennington Biomedical Research Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* Both genders and all races will be invited to participate * 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 * BMI \> 19 and \< 35 * Age 18-30
Exclusion criteria
* Smokers * Unwilling or unable to abstain from alcohol consumption and caffeine consumption prior to testing and laboratory * Significant renal, hepatic, endocrine, pulmonary, cardiac or hematological disease * Pregnancy * 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 For the MRI, the following
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Characteristics of Individuals | 4 days of high fat diet | Characterize the biochemical, endocrine, anthropometric and environmental characteristics of individuals with the thrifty phenotype. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Identify the Signaling Pathways | 4 days after high fat diet | Identify the signaling pathways in skeletal muscle that are dysregulated in individuals with the thrifty phenotype through mRNA expression profiling in skeletal tissue. |
Countries
United States
Outcome results
None listed