Clinical trial NCT02621294: Measuring Protein Requirement Using Amino Acid Oxidation in Strength and Endurance Athletes
Official title: Measuring Protein Requirement Using the Indicator Amino Acid Oxidation Method in Healthy Young Strength and Endurance Exercise Trained Individuals
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Protein Requirement of Athletes
Keywords: Protein
indicator amino acid oxidation method
athletes
Lead sponsor: University of Western Ontario, Canada
Sponsor class: OTHER
First posted: 2015-12-03
Enrollment: 16
Sex: ALL
Minimum age (years): 18
Maximum age (years): 30
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP

Brief summary: Our objective is to determine the dietary requirement of protein for strength and endurance exercise trained (more than 4 months training experience) individuals between 18 - 30 years of age using the indicator amino acid oxidation (IAO) method. This study will be the first to determine the required quantity of protein need per day in strength- and endurance trained young adults using the IAO method.

Detailed description: The adequacy of the protein dietary requirement for strength (ST) and endurance (ET) exercise trained individuals has been a subject of considerable debate for many years and, at present, there is a discrepancy between those who establish dietary protein requirements for healthy adults and those issuing guidelines for athletes. Despite past nitrogen balance studies suggesting a greater protein requirement in ST and ET athletes, the Institute of Medicine (2005) recommends "no additional dietary protein for healthy adults undertaking resistance or endurance exercise". Current protein and amino acid (AA) requirement estimates for adults are based on nitrogen balance data which are considered to be flawed due to several methodological problems including the use of single linear regression for analyzing nonlinear data and an over/underestimation of nitrogen intake and excretion, respectively. To overcome these problems, the indicator amino acid oxidation technique (IAO) was developed for determination of dietary AA or protein requirements. The IAO method is based on the concept that when dietary protein is inadequate, all AA, including the indicator AA, will be oxidized. With increasing total protein intake, oxidation of the indicator AA will decrease. Once the requirement is met, there is no further change in the oxidation of the indicator AA and the inflection or 'breakpoint' is the estimated requirement. A mixed-effects change-point regression analysis to F13CO2 (label tracer oxidation in 13CO2 breath) in response to graded amounts of protein will be utilized to over come the limitations of linear regression previously used with nitrogen balance. These protein requirement measures using the IAO has not been carried out on ST or ET individuals previously so this will be the first study to do so. The results of this study will help determine the optimal protein requirement in ST and ET athletes which is important not only for athletes but also for older individuals whose loss of muscle mass has been linked to a variety of health concerns.

Eligibility criteria: Inclusion Criteria:

Healthy strength-trained and endurance-trained (more than 3 months training experience, at least 3x week) individuals (18-30 years old).

Exclusion Criteria:

* Unhealthy,
* sedentary individuals,
* those who are taking medication,
* those outside the age range, or
* those who have milk allergies

Primary outcomes:
measure: measurement of protein requirement as a response of 13C oxidation (µmol . kg-1 . h-1) of 13C-Phenylalanine to varied graded intakes of protein (g/kg/d) in form of amino acid mixture based on egg protein profile
timeFrame: within 8 hours of feeding period
Secondary outcomes:
measure: Measuring body composition (percent fat and fat free mass) using air displacement plethysmography (BOD POD)
timeFrame: 10 minutes fasted in the morning
measure: Measuring resting energy expenditure (kcal/d) using an open-circuit indirect calorimetry
timeFrame: 40 minutes fasted in the morning
Other outcomes:
Locations:
city: London
country: Canada
facility: Exercise Nutrition Research Laboratory
state: Ontario
Study officials:
affiliation: Western University
name: Peter Lemon, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Bandegan A, Courtney-Martin G, Rafii M, Pencharz PB, Lemon PWR. Indicator amino acid oxidation protein requirement estimate in endurance-trained men 24 h postexercise exceeds both the EAR and current athlete guidelines. Am J Physiol Endocrinol Metab. 2019 May 1;316(5):E741-E748. doi: 10.1152/ajpendo.00174.2018. Epub 2019 Feb 19.
citation: Bandegan A, Courtney-Martin G, Rafii M, Pencharz PB, Lemon PW. Indicator Amino Acid-Derived Estimate of Dietary Protein Requirement for Male Bodybuilders on a Nontraining Day Is Several-Fold Greater than the Current Recommended Dietary Allowance. J Nutr. 2017 May;147(5):850-857. doi: 10.3945/jn.116.236331. Epub 2017 Feb 8.