Influence of Habitual Protein Intake on AA Tracer Oxidation

NCT ID: NCT03845569

Last Updated: 2019-02-19

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 5 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2017-11-01
• Study Completion Date: 2018-04-18

Brief Summary

Protein is an essential nutrient that one's diet to maintain important bodily functions and to recover from exercise. Currently, the Indicator Amino Acid Oxidation method (IAAO) has been used to determine protein requirements in a variety of populations including children, neonates, the elderly and recently, resistance trained populations. This study serves to test the robustness of the IAAO method and to determine if high habitual dietary protein intake, as seen in resistance trained males, has the potential to influence the protein requirements determined by the IAAO method. Further, the current study also aims to determine how the body metabolizes or uses dietary protein and how it might change when consuming a protein intake that is less than what is habitually consumed.

Detailed Description

This study employed a two-phase randomized crossover design, where participants performed both a High/Habitual protein phase and a moderate protein phase. The Habitual protein phase is designed to model resistance trained individual's habitual protein consumption by providing 2.2g/kg/d in a controlled diet. The Moderate protein phase is designed to investigate the impact of decreasing dietary protein intake to a moderate amount (1.2g/kg/d) over five days on protein metabolism. Both phases used the stable isotope L-[1-13C]Phenylalanine and metabolic trails were modelled after the indicator amino acid oxidation (IAAO) technique.

High Protein Phase The high protein phase is three days in length, with diet-controlled throughout, and a metabolic trail on day 3. Participants will perform whole-body resistance exercise on days one and three.

Moderate protein phase The Moderate protein phase is seven days in length, with MT on days three, five and seven. Dietary intake will be controlled throughout the whole phase providing either 2.2 g/kg/d of protein (days one and two), or 1.2 g/kg/d (days three through seven). Full body resistance exercise will be performed performed on days one, three, five and seven.

This phase will allow measurement of protein metabolism over five days following a decrease in dietary protein intake, and to determine the effect of dietary changes on the IAAO method.

Conditions

Protein/Amino Acid Metabolism; Indicator Amino Acid Oxidation Method

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: OTHER
• Blinding Strategy: NONE

Study Groups

Habitual Protein phase

A trial investigating protein oxidation/metabolism that was used to model resistance trained individual's habitual dietary protein intake (2.2g/kg/d).

Group Type: OTHER

Three day Controlled Diet

Intervention Type: OTHER

Three days of a controlled diet providing 2.2g/kg/d of dietary protein with protein metabolism measured on day 3. This was used to model the habitual intake of this cohort.

Moderate Protein Phase

A series of three trials over a one week period investigating protein oxidation/metabolism that was used to investigate the metabolic response of decreased protein intake (1.2g/kg/d) over a period of five days (trials on days 1, 3, 5 following reduction in protein intake from 2.2g/kg/d to 1.2g/kg/d) relative to the Habitual protein phase trial.

Group Type: EXPERIMENTAL

Dietary protein intake reduction

Intervention Type: OTHER

Following two days of controlled diet at 2.2g/kg/d of dietary protein, intake was reduced to 1.2g/kg/d for five days, and protein metabolism was measured on days 1, 3, and 5.

Interventions

Dietary protein intake reduction

Following two days of controlled diet at 2.2g/kg/d of dietary protein, intake was reduced to 1.2g/kg/d for five days, and protein metabolism was measured on days 1, 3, and 5.

Intervention Type: OTHER

Three day Controlled Diet

Three days of a controlled diet providing 2.2g/kg/d of dietary protein with protein metabolism measured on day 3. This was used to model the habitual intake of this cohort.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Healthy, weight-trained individuals that have trained consistently for > 1 year
• Habitually dietary protein consumption of 1.9 to 3.0g/kg/d
• Train each muscle group (i.e. chest, back, legs) at least twice a week
• Body mass stable in the last month
• Meets strength relative-to-weight guidelines (adapted from Morton et al., 2016; Chilibeck et -al., 1997)

• Bench Press: - Bodyweight (kg) * 1.25
• Leg Press: - Bodyweight (kg) *4.0

Exclusion Criteria

• Inability to meet health and PA guidelines according to the PAR-Q+
• Inability to adhere to any of the protocol guidelines (e.g. alcohol and caffeine consumption)
• Regular tobacco use, screened by questionnaire
• Illicit drug use (e.g. growth hormone, testosterone, etc.), screened by a survey in training log

• 1 month sedentary in the last 6 months prior to study participation
• 30 minutes of continuous cardio per exercise session
• BMI > or equal to 35
• Individual plans to increase or decrease body mass in the next 3 months
• Use of supplements (excluding whey protein), such as creatine and beta-alanine, in the last 30 days

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 35 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

University of Toronto

OTHER

Sponsor Role: lead

Responsible Party

Daniel Moore

Principle Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Daniel R Moore, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Toronto

Locations

Goldring Centre for High Performance Sport

Toronto, Ontario, Canada

Countries

Canada

References

Tinline-Goodfellow CT, West DWD, Malowany JM, Gillen JB, Moore DR. An Acute Reduction in Habitual Protein Intake Attenuates Post Exercise Anabolism and May Bias Oxidation-Derived Protein Requirements in Resistance Trained Men. Front Nutr. 2020 Apr 22;7:55. doi: 10.3389/fnut.2020.00055. eCollection 2020.

Reference Type: DERIVED

PMID: 32391374 (View on PubMed)

Other Identifiers

HPI

Identifier Type: -

Identifier Source: org_study_id