Fat Metabolism in Response to Acute Diet- and Exercise-induced Changes in Energy Balance

Not Applicable

Completed

• Conditions: Cardiovascular Diseases
• Interventions: Behavioral: Energy balance with exercise; Behavioral: Negative energy balance with exercise; Behavioral: Positive energy balance; Behavioral: Negative energy balance; Behavioral: Energy balance

• Registration Number: NCT00830999
• Lead Sponsor: Washington University School of Medicine

Brief Summary

This study is being conducted to learn more about the role of diet and exercise in regulating plasma triglyceride (fat) metabolism. The investigators will examine the effect of acute (24 hour) changes in energy intake and expenditure on fat metabolism the following day.

Detailed Description

Excess body fat and a sedentary lifestyle are associated with increased plasma triglyceride (TG) and apolipoprotein B-100 (apoB-100) concentrations, which are important risk factors for the development of cardiovascular disease.

Weight loss and endurance exercise improve plasma lipid and lipoprotein concentrations. However, the mechanisms responsible for this effect are largely unknown, and much uncertainty remains regarding the independent roles of dietary energy intake, exercise energy expenditure, and net energy balance in controlling plasma TG concentrations.

The main goal of this project, therefore, is to investigate the mechanisms by which acute alterations in energy balance, induced by diet and/or physical activity (endurance exercise), regulate very-low density lipoprotein (VLDL) metabolism.

Subjects will be asked to perform 3 separate trials. One of these will always be an "energy balance" trial that will act as the control trial for the other 2 trials they perform. Subjects will therefore be randomized to 2 different study arms.

Study Timeline

• Study Start: 2006-04
• Study First Submitted: 2009-01-26
• Study First Submitted QC: 2009-01-26
• Study First Posted: 2009-01-28
• Primary Completion: 2012-12
• Study Completion: 2012-12
• Status Verified: 2013-01
• Last Update Submitted: 2013-01-18
• Last Update Posted: 2013-01-21

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 12

Inclusion Criteria

• overweight and obese men
• normal to mild hypertriglyceridemia

Exclusion Criteria

• Smoking
• Any medical condition other than increased body weight (e.g. diabetes, heart disease, etc.).
• Use of drugs known to affect lipid metabolism (e.g. statins, etc.).
• Regular exercise training.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Positive energy balance	Energy balance	Comparison between isocaloric and hypercaloric diets with no exercise performed in any trials
Energy balance with exercise	Energy balance with exercise	Comparison between an isocaloric diet without exercise and a hypercaloric diet with a sufficient amount of exercise performed to match the excess calories consumed resulting in both trials being in net energy balance.
Energy balance with exercise	Energy balance	Comparison between an isocaloric diet without exercise and a hypercaloric diet with a sufficient amount of exercise performed to match the excess calories consumed resulting in both trials being in net energy balance.
Negative energy balance	Energy balance	Comparison between isocaloric and hypocaloric diets with no exercise performed in any trials
Negative energy balance with exercise	Negative energy balance with exercise	Comparison between consuming an isocaloric diet without exercise and consuming the same amount of calories as in the isocaloric trial but with exercise performed resulting in net negative energy balance in the exercise trial.
Positive energy balance	Positive energy balance	Comparison between isocaloric and hypercaloric diets with no exercise performed in any trials
Negative energy balance	Negative energy balance	Comparison between isocaloric and hypocaloric diets with no exercise performed in any trials
Negative energy balance with exercise	Energy balance	Comparison between consuming an isocaloric diet without exercise and consuming the same amount of calories as in the isocaloric trial but with exercise performed resulting in net negative energy balance in the exercise trial.

Primary Outcome Measures

Name	Time	Method
Very Low Density Lipoprotein-Triglyceride and apoB-100 concentrations	After acute (24 hour) changes in energy intake and/or energy expenditure

Secondary Outcome Measures

Name	Time	Method
Liver Very Low Density Lipoprotein-Triglyceride and apoB-100 secretion rates	After acute (24 hour) changes in energy intake and/or energy expenditure
Plasma insulin concentration	During acute (24 hour) changes in energy intake and/or energy expenditure	Measured hourly over the 24 h period.
Plasma free fatty acid concentration and turnover rate	After acute (24 hour) changes in energy intake and/or energy expenditure
Liver Very Low Density Lipoprotein-Triglyceride and apoB-100 clearance rates from plasma	After acute (24 hour) changes in energy intake and/or energy expenditure
Plasma glucose concentration and turnover rate	After acute (24 hour) changes in energy intake and/or energy expenditure
Plasma glucose concentration	During acute (24 hour) changes in energy intake and/or energy expenditure	Measured hourly over the 24 h period.
Plasma free fatty acid concentration	During acute (24 hour) changes in energy intake and/or energy expenditure	Measured hourly over the 24 h period.

Trial Locations

Locations (1)

Washington University in Saint Louis; 🇺🇸 Saint Louis, Missouri, United States