Leucine requirement determined in healthy young adult males using the indicator amino acid oxidation method.
Am J Clin Nutr
; 2024 Aug 28.
Article
em En
| MEDLINE
| ID: mdl-39209155
ABSTRACT
BACKGROUND:
Previous studies proposed varying leucine requirements for adults ranging from 25 to 40 mgâ kg-1â d-1, but often these studies did not test intakes exceeding 40 mgâ kg-1â d-1. Data using the indicator amino acid oxidation (IAAO) method suggest a higher requirement of 55 mgâ kg-1â d-1 on the basis of the total branched-chain amino acids requirement, but not leucine independently.OBJECTIVES:
The IAAO method was used to determine the leucine requirement in healthy young adult males.METHODS:
Ten healthy adult males (26.9 ± 1.87 y, mean ± SEM) were studied at 7 leucine intakes; each studied over a 3-d period. Following 2-d of preadaptation to adequate protein intake (1.0 gâ kg-1â d-1), subjects received experimental diets containing the randomly assigned test leucine intake (10, 20, 30, 40, 50, 65, and 75 mgâ kg-1â d-1) for 8 h. The rate of the release of 13CO2 from the oxidation of L-[1-13C]phenylalanine (F13CO2) was measured on the third day, and the leucine requirement was determined using mixed-effect change-point regression and the F13CO2 data in R. The 95% confidence interval was calculated using parametric bootstrap. The effect of leucine intake on the concentration of plasma amino acids, insulin, and glucose were assessed using repeated measures analysis of variance and linear mixed effects.RESULTS:
The mean leucine requirement was 33.6 mgâ kg-1â d-1 with a lower and upper 95% confidence of 26.16, 41.04 mgâ kg-1â d-1. Higher leucine intakes were associated with increased plasma leucine, and decreased valine, isoleucine, and serine concentrations.CONCLUSIONS:
The leucine requirement of young adult males is â¼34 mgâ kg-1â d-1, which aligns with previously published tracer balance experiments. This trial was registered at http//clinicaltrials.gov (https//clinicaltrials.gov/study/NCT05394155?term=leucine%20young%20adult&rank=1) as NCT05394155.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Am J Clin Nutr
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Canadá
País de publicação:
Estados Unidos