Dietary Macronutrient Manipulation and Substrate Oxidation During Exercise

The Effect of Dietary Macronutrient Manipulation and Glycogen Depleting Exercise on Substrate Oxidation at Rest and During Exercise

This study will investigate the effect of dietary macronutrient manipulation on glycogen (stored carbohydrate) levels in the muscle and substrate oxidation during exercise. The investigators will investigate the hypothesis that manipulating the macronutrient content of the diet will alter the levels of glycogen in the muscle and, in turn, substrate oxidation during exercise.

Study Overview

• Status: Completed
• Conditions: Dietary Manipulation
• Intervention / Treatment: Other: Diet with a different macronutrient content A; Other: Interval treadmill running exercise; Other: Steady state treadmill running exercise; Other: Diet with a different macronutrient content B; Other: Diet with a different macronutrient content C

Detailed Description

One way to help reduce body fat is to expend more energy from the oxidation of fat as a fuel. Exercise is one way to increase fat oxidation. The extent to which exercise facilitates the use of fat as a fuel may be influenced by an individual's dietary intake.

This study aims to establish the effect of dietary macronutrient manipulation on muscle glycogen levels and substrate oxidation during exercise. Participants will undertake three separate trial periods. During each trial period participants will consume a diet containing different macronutrient compositions. For each of the trials the investigators will assess how the macronutrient composition of the diet affects muscle glycogen level and substrate oxidation during exercise.

• Study Type: Interventional
• Enrollment (Actual): 13
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Birmingham, United Kingdom, B15 2TT
    • School of Sport Exercise and Rehabilitation Sciences, University of Birmingham

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Good general health
• Non-smoking - currently and for the past 5 years
• Fitness - V̇O2max 40-60 ml/kg/min
• Body mass index (20-25 kg/m2)

Exclusion Criteria:

• Known or suspected intolerance to the dietary interventions or their stated ingredients.
• Participation in another clinical study or receipt of an investigational drug within 30 days of the screening visit.
• Previous participation in this study.
• Recent history (within the last year) of alcohol or other substance abuse.
• An employee of the sponsor or the study site or members of their immediate family.
• Abnormal / extreme habitual dietary practice / intake
• Recent (≤3 months) dietary practice that may be deemed as low and/or high in macronutrients will be excluded.
• The taking of any prescribed medication

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental arm 1; One of three 7-day study arms consisting of 3 days of standardised diet followed by 3 days of dietary macronutrient manipulation and 1 day of experimental testing.	Other: Diet with a different macronutrient content A; A diet with altered macronutrient content will be provided to participants on days 4-6 of experimental arm 1.; Other: Interval treadmill running exercise; Participants will perform interval treadmill running exercise on days 4 and 5 of all experimental arms.; Other: Steady state treadmill running exercise; Participants will perform steady state treadmill running exercise on day 7 of all experimental arms.
Experimental: Experimental arm 2; One of three 7-day study arms consisting of 3 days of standardised diet followed by 3 days of dietary macronutrient manipulation and 1 day of experimental testing.	Other: Interval treadmill running exercise; Participants will perform interval treadmill running exercise on days 4 and 5 of all experimental arms.; Other: Steady state treadmill running exercise; Participants will perform steady state treadmill running exercise on day 7 of all experimental arms.; Other: Diet with a different macronutrient content B; A diet with a different macronutrient content compared to arm 1 will be provided to participants on days 4-6 of experimental arm 2.
Experimental: Experimental arm 3; One of three 7-day study arms consisting of 3 days of standardised diet followed by 3 days of dietary macronutrient manipulation and 1 day of experimental testing.	Other: Interval treadmill running exercise; Participants will perform interval treadmill running exercise on days 4 and 5 of all experimental arms.; Other: Steady state treadmill running exercise; Participants will perform steady state treadmill running exercise on day 7 of all experimental arms.; Other: Diet with a different macronutrient content C; A diet with a different macronutrient content compared to arms 1 and 2 will be provided to participants on days 4-6 of experimental arm 3.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Muscle glycogen concentration after dietary macronutrient manipulation	Muscle glycogen concentration will be measured after the dietary macronutrient manipulation intervention.	Day 7 of all experimental arms

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of fat oxidation at rest (g/min)	Whole body oxygen consumption (VO2, L/min) and carbon dioxide production (VCO2, L/min) at rest will be measured using indirect calorimetry to calculate the rate of fat oxidation at rest (g/min).	For 20 min on Day 7 of all experimental arms
Rate of fat oxidation during exercise (g/min)	Whole body oxygen consumption (VO2, L/min) and carbon dioxide production (VCO2, L/min) during exercise will be measured using indirect calorimetry to calculate the rate of fat oxidation during exercise (g/min).	During 60 min of exercise on day 7 of all experimental arms
Rate of carbohydrate oxidation at rest (g/min)	Whole body oxygen consumption (VO2, L/min) and carbon dioxide production (VCO2, L/min) at rest will be measured using indirect calorimetry to calculate the rate of carbohydrate oxidation at rest (g/min).	For 20 min on Day 7 of all experimental arms
Rate of carbohydrate oxidation during exercise (g/min)	Whole body oxygen consumption (VO2, L/min) and carbon dioxide production (VCO2, L/min) during exercise will be measured using indirect calorimetry to calculate the rate of carbohydrate oxidation during exercise (g/min).	During 60 min of exercise on day 7 of all experimental arms
Blood glucose concentration	Blood glucose concentration will be assessed in blood samples taken during exercise.	At 0, 20, 40 and 60min into exercise on day 7 of all experimental arms.
Blood insulin concentration	Blood insulin concentration will be assessed in blood samples taken during exercise.	At 0, 20, 40 and 60min into exercise on day 7 of all experimental arms
Blood fatty acid concentration	Blood fatty acid concentration will be assessed in blood samples taken during exercise.	At 0, 20, 40 and 60min into exercise on day 7 of all experimental arms
Change in intramuscular triglyceride (IMTG) content after exercise	IMTG utilisation during exercise (or change in IMTG content pre-post exercise) will be measured by comparing the IMTG content before and after exercise.	IMTG content measured just before and immediately after 60min of exercise on Day 7 of all experimental arms

Collaborators and Investigators

• Sponsor: University of Birmingham
• Collaborators: Lucozade Ribena Suntory
• Investigators: Principal Investigator: Gareth A Wallis, PhD, University of Birmingham

Study record dates

Study Major Dates

• Study Start: January 1, 2016
• Primary Completion (Actual): June 1, 2017
• Study Completion (Actual): June 1, 2017

Study Registration Dates

• First Submitted: November 6, 2015
• First Submitted That Met QC Criteria: November 11, 2015
• First Posted (Estimate): November 16, 2015

Study Record Updates

• Last Update Posted (Actual): October 11, 2018
• Last Update Submitted That Met QC Criteria: October 10, 2018
• Last Verified: October 1, 2018

More Information

Terms related to this study

• Other Study ID Numbers: ERN_15-0963

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No