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

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.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Other: Physical Activity Level

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

• Study Type: Interventional
• Enrollment (Actual): 17
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Louisiana
    • Baton Rouge, Louisiana, United States, 70808
      • Pennington Biomedical Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
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	One Year

Collaborators and Investigators

• Sponsor: Pennington Biomedical Research Center
• Collaborators: University of Washington
• Investigators: Principal Investigator: Steven Smith, Pennington Biomedical Research Center; Principal Investigator: George Bray, Pennington Biomedical Research Center

Study record dates

Study Major Dates

• Study Start: May 1, 2007
• Primary Completion (Actual): March 1, 2009
• Study Completion (Actual): June 1, 2020

Study Registration Dates

• First Submitted: January 28, 2008
• First Submitted That Met QC Criteria: February 7, 2008
• First Posted (Estimate): February 8, 2008

Study Record Updates

• Last Update Posted (Actual): September 21, 2022
• Last Update Submitted That Met QC Criteria: September 16, 2022
• Last Verified: January 1, 2016

More Information

Terms related to this study

• Keywords: exercise; activity; adaptation to high fat diet
• Other Study ID Numbers: PBRC 27017; 58-6535-5-071