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Mechanisms of the Effect of Physical Activity on the Adaptation to a High-Fat Diet

This study is ongoing, but not recruiting participants.
University of Washington
Information provided by (Responsible Party):
George A. Bray, Pennington Biomedical Research Center Identifier:
First received: January 28, 2008
Last updated: January 22, 2016
Last verified: January 2016
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.

Condition Intervention
Other: Physical Activity Level

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single Blind (Care Provider)
Primary Purpose: Basic Science
Official Title: Mechanisms of the Effect of Physical Activity on the Adaptation to a High-Fat Diet

Resource links provided by NLM:

Further study details as provided by George A. Bray, Pennington Biomedical Research Center:

Primary Outcome Measures:
  • 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 ]

Estimated Enrollment: 24
Study Start Date: May 2007
Estimated Study Completion Date: June 2020
Primary Completion Date: March 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
High intensity exercise and high fat diet
Other: Physical Activity Level
High vs. low physical activity during a high fat diet consumption.
Experimental: 2
Low intensity exercise and high fat diet
Other: Physical Activity Level
High vs. low physical activity during a high fat diet consumption.

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

Ages Eligible for Study:   18 Years to 35 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

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
  • Smokers
  • 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
  • Unable or unwilling to perform treadmill walking at the required speed and incline to achieve 1.8*RMR
  • History or family history of blood clots deep vein thrombosis or pulmonary embolism)
  • Poor circulation, bypass operation on legs, blood coagulation disorders, diagnosed peripheral arterial or vascular disease, cramping pain in your muscle during exercise or nerve damage in your legs.
  • You had major surgery on the abdomen, pelvis or legs within previous 3 months.
  • You have cancer
  • You have rheumatoid disease/ walking or joint problems
  • You are claustrophobic
  • You are depressed or have an eating disorder
  • You demonstrate a style of interpersonal relationships that would inhibit successful completion of the study

For the MRS / 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 with bridgework held in place by magnets
  Contacts and Locations
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Please refer to this study by its identifier: NCT00611117

United States, Louisiana
Pennington Biomedical Research Center
Baton Rouge, Louisiana, United States, 70808
Sponsors and Collaborators
Pennington Biomedical Research Center
University of Washington
Principal Investigator: Steven Smith Pennington Biomedical Research Center
Principal Investigator: George Bray Pennington Biomedical Research Center
  More Information

Responsible Party: George A. Bray, Princiapal Investigator, Pennington Biomedical Research Center Identifier: NCT00611117     History of Changes
Other Study ID Numbers: PBRC 27017
Study First Received: January 28, 2008
Last Updated: January 22, 2016

Keywords provided by George A. Bray, Pennington Biomedical Research Center:
adaptation to high fat diet
exercise processed this record on May 25, 2017