title: Evaluation of the protein requirement in Chinese young adults using the indicator amino acid oxidation technique.
abstract: OBJECTIVE
  To accurately calculate the protein requirements in Chinese young adults using the indicator amino acid oxidation technique.
  
  
  METHODS
  Nine women and ten men received a restricted daily level of protein intake (0.75, 0.82, 0.89, 0.97, and 1.05 g/kg), along with L-[1-13C]-leucine. Subjects' protein requirement was determined by a biphasic linear regression crossover analysis of F13CO2 data. In doing so, a breakpoint at the minimal rate of appearance of 13CO2 expiration specific to each level of dietary protein was identified. This trial was registered with the Chinese clinical trial registry as ChiCTR-ONC-11001407.
  
  
  RESULTS
  The Estimated Average Requirement (EAR) and the Recommended Nutrient Intake (RNI) of protein for healthy Chinese young adults were determined to be 0.87 and 0.98 g/(kg•d), respectively, based on the indicator amino acid oxidation technique.
  
  
  CONCLUSIONS
  The EAR and RNI of mixed protein are 5% and 16% that are lower than the current proposed EAR and RNI (0.92 and 1.16 g/(kg•d), respectively), as determined by the nitrogen balance method. The respective EAR and RNI recommendations of 0.87 and 0.98 g/(kg•d) of mixed protein are estimated to be reasonable and suitable for Chinese young adults.
authors: Key Laboratory of Trace Element Nutrition, MOH, Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
authors: Min
authors: M
authors: Li
authors: Zhi Ling
authors: ZL
authors: Wang
authors: Ling Yan
authors: LY
authors: Gou
authors: Wei Dong
authors: WD
authors: Li
authors: Yuan
authors: Y
authors: Tian
authors: Yi Chun
authors: YC
authors: Hu
authors: Rui
authors: R
authors: Wang
authors: Jian Hua
authors: JH
authors: Piao
authors: Xiao Guang
authors: XG
authors: Yang
authors: Yu Hui
authors: YH
authors: Zhang
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000378:metabolism*; D001823:Body Composition; D001835:Body Weight; D001944:Breath Tests; D002245:Carbon Dioxide / Q000032:analysis; D004044:Dietary Proteins / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D009751:Nutritional Requirements; D010084:Oxidation-Reduction; D055815:Young Adult
chemical_list: D000596:Amino Acids; D004044:Dietary Proteins; D002245:Carbon Dioxide
keywords: Adult protein intake; Biphasic linear regression crossover analysis; Indicator amino acid oxidation; Mixed diet; Protein requirement