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Protein requirements in healthy school‐age children determined by using the indicator amino acid oxidation technique
Author(s) -
Elango Rajavel,
Humayun Mohammad A,
Ball Ronald O,
Pencharz Paul B
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.869.19
Subject(s) - energy requirement , phenylalanine , protein requirement , population , zoology , crossover study , amino acid , urine , chemistry , medicine , biochemistry , biology , mathematics , regression , statistics , environmental health , alternative medicine , pathology , body weight , placebo
Protein (PRO) requirements in school‐age children were determined by the indicator amino acid oxidation (IAAO) method. Four, healthy children (8 – 11 yr) each randomly received a minimum of three PRO intakes below 0.9 and three intakes above 0.9 g/kg/d; range = 0.16 – 1.84 g/kg/d. The diets were isocaloric and provided energy at 1.7 X REE. PRO was given as an amino acid mixture based on egg protein composition, except phenylalanine which was maintained constant across intakes. PRO requirements were determined by measuring the oxidation of L‐[1‐ 13 C]‐phenylalanine to 13 CO 2 ( F 13 CO 2 ). Breath and urine samples were collected at baseline and isotopic steady state. Linear regression crossover analysis identified a breakpoint (requirement) at minimal F 13 CO 2 in response to different PRO intakes. Preliminary results indicate the mean and population‐safe PRO requirements to be 1.35 and 1.59 g/kg/d, respectively. These results are significantly higher than the mean and population‐safe PRO requirements of 0.76 and 0.95 g/kg/d, respectively, currently recommended by the Dietary Reference Intakes (DRI 2005) for macronutrients This study is the first to directly estimate protein requirements in children and suggests that the current recommendations, based on a factorial method are severely underestimated. (CIHR supported)