ADAPT The Adaptation to High Fat Diets Extention

Study Overview
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Brief Summary
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This study is designed to predict weight gain overtime after a high fat diet.

Detailed Description
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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.

Official Title
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ADAPT-The Adaptation to High Fat Diets

Conditions
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Healthy

Intervention / Treatment
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* Behavioral: High Fat Diet
* Behavioral: Low Fat Diet


Participation Criteria
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Eligibility Criteria
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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 exclusion criteria apply: Individuals who have a heart pacemaker, defibrillator, or non-removable hearing aid Individuals with any clips or metal plates in their head Individuals who have any artificial limbs or prosthetic devices Individuals who were ever injured by a metallic foreign body which was not removed Individuals, who wear braces on their teeth, have non-removable false teeth, or removable bridgework

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Lifestyle<br>Measurement of body weight in a fown with light undercloting (30 minutes) and height. | Behavioral: High Fat Diet<br>* Daily eating<br>* Other names: Measurements will be collected to help with gathering data.;|
| Other: DEXA Scanner<br>Low-dose X0rays to determine the amount of fat, bone and muscle in your body. | Behavioral: Low Fat Diet<br>* Life style eating habits<br>* Other names: Questionnairs of food frequency;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Characteristics of Individuals | Characterize the biochemical, endocrine, anthropometric and environmental characteristics of individuals with the thrifty phenotype. | 4 days of high fat diet | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Identify the Signaling Pathways | Identify the signaling pathways in skeletal muscle that are dysregulated in individuals with the thrifty phenotype through mRNA expression profiling in skeletal tissue. | 4 days after high fat diet |