Overview

This trial is active, not recruiting.

Condition dietary modification
Treatments high fat, normal, normal + extra fat
Sponsor University of Birmingham
Collaborator GlaxoSmithKline
Start date March 2015
End date June 2016
Trial size 16 participants
Trial identifier NCT02568592, ERN_15-0012

Summary

The capacity to burn fat as fuel for exercise may have important implications for sporting performance, with dietary fat intake positively influencing this ability.

Endurance performance and the ability to burn fat will be measured in women runners following the consumption of 3 diets varying in the amount of fat and carbohydrate.

United States No locations recruiting
Other Countries No locations recruiting

Study Design

Allocation randomized
Intervention model crossover assignment
Masking open label
Primary purpose basic science
Arm
(Experimental)
High Fat - Carbohydrate (20%), Fat (65%), Protein (15%)
high fat
High Fat - Carbohydrate (20%), Fat (65%), Protein (15%)
(Experimental)
Normal - Carbohydrate (50%), Fat (35%) and Protein (15%)
normal
Normal - Carbohydrate (50%), Fat (35%) and Protein (15%)
(Experimental)
Normal + Extra Fat - Carbohydrate (50%), Fat (65%), Protein (15%). Carbohydrate and protein intake identical in absolute amounts to NORM (Normal), with an additional 30% extra energy coming from fat.
normal + extra fat
Normal + Extra Fat - Carbohydrate (50%), Fat (65%), Protein (15%). Carbohydrate and protein intake identical in absolute amounts to NORMAL, with an additional 30% extra energy coming from fat.

Primary Outcomes

Measure
Rates of fat oxidation during exercise
time frame: 90 minutes of sub-maximal exercise

Secondary Outcomes

Measure
5km running performance
time frame: Immediately following measurement of Primary Outcome measure
Change in plasma glucose concentration
time frame: 90 minutes sub-maximal exercise
Change in Free Fatty Acid concentration
time frame: 90 minutes sub-maximal exercise
Change in plasma glycerol concentration
time frame: 90 minutes sub-maximal exercise

Eligibility Criteria

Female participants from 18 years up to 45 years old.

Inclusion Criteria: - BMI >17.0 < 25 kg/m2 - Good General Health - Accustomed to vigorous physical activity - Run > 2 times per week - V̇O2max >50ml/kg/min - Weight Stable > last 6months - Non Smoker - Pre-menopausal, and either eumenorrheic and regularly menstruating, or using monophasic hormonal oral contraceptives for > 3 months. Exclusion Criteria: - Currently taking part in another scientific/clinical study - Taking any prescription drug / supplement thought to influence metabolism - Following unusual dietary practices (such as intermittent fasting or low carbohydrate diets) - Pregnant - Breast Feeding

Additional Information

Official title Exercise Substrate Utilisation and Endurance Performance Following Short-term Manipulation of Dietary Fat Intake in Women
Principal investigator Gareth A Wallis, PhD
Description Dietary fat intake positively influences the ability to burn fat during exercise in women but not men, whereas carbohydrate intake negatively influences fat oxidation in both sexes. The independent nature of dietary fat intake as a predictor of the ability to burn fat in women suggests that in conditions of adequate carbohydrate intake providing additional fat may increase fat oxidation in women whereas it does not in men. It is of interest to explore if indeed women are responsive (i.e., increase in fat oxidation) to short-term increases in dietary fat intake induced by overfeeding (adequate carbohydrate) or if as appears to be the case in men reduced carbohydrate intake as typically employed in high-fat, low carbohydrate dietary studies is also a prerequisite for enhancing fat oxidation in women, and whether this translates into a difference in exercise endurance performance.
Trial information was received from ClinicalTrials.gov and was last updated in May 2016.
Information provided to ClinicalTrials.gov by University of Birmingham.