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

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

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.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Diseases
• Intervention / Treatment: Behavioral: Positive energy balance; Behavioral: Energy balance; Behavioral: Energy balance with exercise; Behavioral: Negative energy balance; Behavioral: Negative energy balance with exercise

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 Type: Interventional
• Enrollment (Actual): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Missouri
    • Saint Louis, Missouri, United States, 63110
      • Washington University in Saint Louis

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Positive energy balance; Comparison between isocaloric and hypercaloric diets with no exercise performed in any trials	Behavioral: Positive energy balance; Subjects will consume over a 24 hour period 33% more calories than they require to meet their energy demands.; Behavioral: Energy balance; Subjects will consume over a 24 hour period a sufficient amount of calories to meet their energy needs.
Experimental: 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.	Behavioral: Energy balance; Subjects will consume over a 24 hour period a sufficient amount of calories to meet their energy needs.; Behavioral: Energy balance with exercise; Subjects will consume over a 24 hour period 33% more calories than they require to meet their energy demands but will perform 2 hours of exercise that will be sufficient to burn off the excess calories consumed resulting in subjects being in net energy balance.
Experimental: Negative energy balance; Comparison between isocaloric and hypocaloric diets with no exercise performed in any trials	Behavioral: Energy balance; Subjects will consume over a 24 hour period a sufficient amount of calories to meet their energy needs.; Behavioral: Negative energy balance; Subjects will consume over a 24 h period only 66% of the calories required to meet their energy demands such that they will be in a net negative calorie balance in this trial.
Experimental: 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.	Behavioral: Energy balance; Subjects will consume over a 24 hour period a sufficient amount of calories to meet their energy needs.; Behavioral: Negative energy balance with exercise; Subjects will consume over a 24 hour period the same amount of calories as ingested in the isocaloric trial but will also perform 2 hours of exercise that will be sufficient to burn off a third of the calories they consumed during this day resulting in subjects being in net negative energy balance in this trial

What is the study measuring?

Primary Outcome Measures

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

Secondary Outcome Measures

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

Collaborators and Investigators

• Sponsor: Washington University School of Medicine

Publications and helpful links

General Publications

• Smith GI, Magkos F, Reeds DN, Okunade AL, Patterson BW, Mittendorfer B. One day of mixed meal overfeeding reduces hepatic insulin sensitivity and increases VLDL particle but not VLDL-triglyceride secretion in overweight and obese men. J Clin Endocrinol Metab. 2013 Aug;98(8):3454-62. doi: 10.1210/jc.2013-1786. Epub 2013 Jun 7.

Study record dates

Study Major Dates

• Study Start: April 1, 2006
• Primary Completion (Actual): December 1, 2012
• Study Completion (Actual): December 1, 2012

Study Registration Dates

• First Submitted: January 26, 2009
• First Submitted That Met QC Criteria: January 26, 2009
• First Posted (Estimate): January 28, 2009

Study Record Updates

• Last Update Posted (Estimate): January 21, 2013
• Last Update Submitted That Met QC Criteria: January 18, 2013
• Last Verified: January 1, 2013

More Information

Terms related to this study

• Keywords: exercise; liver; lipoproteins; triglycerides; fat metabolism
• Additional Relevant MeSH Terms: Cardiovascular Diseases
• Other Study ID Numbers: 05-0195