scholarly journals Protein Requirements of Elderly Chinese Adults Are Higher than Current Recommendations

2020 ◽  
Vol 150 (5) ◽  
pp. 1208-1213 ◽  
Author(s):  
Deqian Mao ◽  
Fengge Chen ◽  
Rui Wang ◽  
Ping Bai ◽  
Yanhong Zhang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Healthy Adult ◽  
The Elderly ◽  
Acid Oxidation ◽  
Adult Women ◽  
Chinese Adults ◽  
Amino Acid Oxidation ◽  
Protein Requirements ◽  
Healthy Elderly ◽  
Elderly Chinese

ABSTRACT Background Due to a lack of research data on the protein requirements of the elderly in China, the estimated average requirement (EAR) and the recommended nutrient intake (RNI) of protein in the elderly remain the same as those in young and middle-aged people at 0.98 g/(kg·d). Objective The objective of this study was to determine the protein requirements of healthy Chinese adults >65y old through use of the indicator amino acid oxidation (IAAO) method. Methods Seven healthy adult men and 7 healthy adult women participated in the study, with protein intakes ranging from 0.3 to 1.8 g/(kg·d). The diets were isocaloric and provided energy at a 1.5 resting energy expenditure. Protein was given based on the lactalbumin. Phenylalanine and tyrosine were added to protein doses of 0.3–1.5 g/kg according to the highest dose of protein content [1.8 g/(kg·d)]. Phenylalanine and tyrosine concentrations were kept constant at each protein dose. The mean protein requirement was determined by applying a nonlinear mixed-effects model analysis to the F13CO2, which identified a breakpoint in F13CO2 in response to graded amounts of protein. This trial was registered with the Chinese clinical trial registry as ChiCTR-BOC-17010930. Results Protein EAR and RNI for healthy elderly Chinese adults were determined to be 0.91 and 1.17 g/(kg·d), respectively, based on the indicator amino acid oxidation technique. Conclusions The estimates of protein requirements for Chinese adults >65 y in the present study are 3.4% and 19.4% higher than the current estimated requirements, 0.88 g/(kg·d) for EAR and 0.98 g/(kg·d) for RNI.

scholarly journals Indicator amino acid oxidation protein requirement estimate in endurance-trained men 24 h postexercise exceeds both the EAR and current athlete guidelines

2019 ◽  
Vol 316 (5) ◽  
pp. E741-E748 ◽  
Author(s):  
Arash Bandegan ◽  
Glenda Courtney-Martin ◽  
Mahroukh Rafii ◽  
Paul B. Pencharz ◽  
Peter W. R. Lemon
Keyword(s):  
Amino Acid ◽  
Dietary Protein ◽  
Protein Pattern ◽  
Training Session ◽  
Acid Mixture ◽  
Acid Oxidation ◽  
Institute Of Medicine ◽  
Protein Requirement ◽  
Amino Acid Oxidation ◽  
Protein Requirements

Despite studies indicating increased protein requirements in strength-trained or endurance-trained (ET) individuals, the Institute of Medicine has concluded that “no additional dietary protein is suggested for healthy adults undertaking resistance or endurance exercise,” and the controversy regarding exercise effects on protein requirements continues. The objective of this study was to determine the dietary protein requirement of healthy young ET men (≥1 yr training experience) 24 h post exercise (to minimize any acute effects of the previous training session) by measuring the oxidation of ingested l-[1-13C]phenylalanine to 13CO2 in response to graded intakes of protein (indicator amino acid oxidation technique). Eight men [maximal oxygen consumption 64.1 ml·kg−1·min−1 (SD 3.7)] were each studied 24 h postexercise repeatedly with protein intakes ranging from 0.3 to 3.5 g·kg−1·day−1. Protein was fed as an amino acid mixture based on the protein pattern in egg, except for phenylalanine and tyrosine, which were maintained at constant amounts across all protein intakes. For 2 days before the study day, all participants consumed 1.6 g protein·kg−1·day−1. The estimated average requirement (EAR) for protein was determined by applying a nonlinear mixed-effects change-point regression analysis to F13CO2 (label tracer oxidation in 13CO2 breath), which identified a breakpoint in the F13CO2 in response to the graded amounts of protein. The EAR for protein and the upper 95% confidence interval were 2.1 and 2.6 g·kg−1·day−1, respectively. These data suggest that the protein EAR for ET men 24 h postexercise exceeds the Institute of Medicine EAR and established athlete guidelines by ~3.5- and 1.3-fold, respectively.

scholarly journals Adaptation of in vivo amino acid kinetics facilitates increased amino acid availability for fetal growth in adolescent and adult pregnancies alike

2014 ◽  
Vol 112 (11) ◽  
pp. 1779-1786 ◽  
Author(s):  
Minerva M. Thame ◽  
Jean W. Hsu ◽  
Raquel Gibson ◽  
Tameka M. Baker ◽  
Grace J. Tang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Adolescent Girls ◽  
Phase 1 ◽  
Acid Oxidation ◽  
Adult Women ◽  
Protein Breakdown ◽  
Adult Group ◽  
Phase 1 Study ◽  
Adolescent Group ◽  
Amino Acid Oxidation

During pregnancy, adult women with a normal BMI synthesise extra amino acids after an overnight fast by increasing body protein breakdown and decreasing amino acid oxidation. It is not known whether adolescent girls can make these adaptations during pregnancy. The present study aimed to measure and compare the protein, glutamine and alanine kinetics of adult women and adolescent girls at early-, mid- and late-pregnancy. Kinetics were measured in the overnight fasted state using intravenous infusions of 13C-leucine, 15N-glutamine and 15N-alanine in ten adults and twenty adolescents aged 14–17 years in the first and second trimesters (phase 1 study) and infusions of 13C-leucine and 15N2-urea in ten adults and eleven adolescents aged 16–17 years in the first and third trimesters (phase 2 study). In phase 1 study, there were no significant differences between the groups with regard to any of the kinetic parameters measured. In both groups, leucine flux increased (P< 0·05), the percentage of leucine flux oxidised decreased (P< 0·05) and non-oxidative leucine disposal to protein synthesis increased (P< 0·05) from the first to the second trimester. In phase2 study, leucine flux was significantly slower (P< 0·05) in the adult group than in the adolescent group during both trimesters, and whole-body leucine flux and non-oxidative leucine disposal increased significantly in the adolescent group (P< 0·05, respectively) and were higher in the adult group from the first to the third trimester. These results suggest that similar to their adult counterparts after an overnight fast, adolescent girls with a normal BMI provide extra amino acids required for net protein deposition during pregnancy by increasing protein breakdown and decreasing amino acid oxidation.

Protein and Amino Acid Requirements of Adults: Current Controversies

2001 ◽  
Vol 26 (S1) ◽  
pp. S130-S140 ◽  
Author(s):  
D. Joe Millward
Keyword(s):  
Amino Acid ◽  
Nitrogen Loss ◽  
Acid Oxidation ◽  
Minimum Requirement ◽  
Amino Acid Oxidation ◽  
Protein Requirements ◽  
Wide Range ◽  
Amino Acid Requirements ◽  
Exercise Induced ◽  
Reported Data

Protein intakes vary widely but costs and benefits of such variation is a long standing unresolved issue. The wide range of reported values for the minimum protein intakefor N equilibrium in adults, i.e. 0.39 to 1. 09 g/kg is best explained by an Adaptive Metabolic Demands model in which metabolic demands include amino acid oxidation at a rate varying with habitual protein intake and which changes slowly with dietary change. Thus within the reported data the true minimum requirement intake, the lowest values in the range at intakes approaching the Obligatory Nitrogen Loss, allows onlyfully adaptedsubjects to achieve N equilibrium. The higher values reflect incomplete adaptation. 13C-1 leucine tracer balance studies of this model show (a) a fall with age in apparent protein requirements, (b) better than predicted efficiency of wheat protein utilization, and (c) controversially, lower lysine requirements than other workers, consistent with new evidence ofde novo synthesis of lysine from urea salvaged by large bowel microflora. The main implication of the requirements model for athletes on high protein diets is increased exercise induced amino acid oxidation and risk of loss ofbody N when such high intakes are not maintained.

scholarly journals Recent advances in determining protein and amino acid requirements in humans

2012 ◽  
Vol 108 (S2) ◽  
pp. S22-S30 ◽  
Author(s):  
Rajavel Elango ◽  
Ronald O. Ball ◽  
Paul B. Pencharz
Keyword(s):  
Amino Acid ◽  
Invasive Technique ◽  
Acid Oxidation ◽  
Amino Acid Oxidation ◽  
Protein Requirements ◽  
Non Invasive ◽  
The Past ◽  
Dietary Amino Acid ◽  
Amino Acid Requirements ◽  
Limiting Amino Acid

During the past 25 years a significant amount of research has been conducted to determine amino acid requirements in humans. This is primarily due to advancements in the application of stable isotopes to examine amino acid requirements. The indicator amino acid oxidation (IAAO) method has emerged as a robust and minimally invasive technique to identify requirements. The IAAO method is based on the concept that when one indispensable dietary amino acid (IDAA) is deficient for protein synthesis, then the excess of all other IDAA, including the indicator amino acid, will be oxidized. With increasing intakes of the limiting amino acid, IAAO will decrease, reflecting increasing incorporation into protein. Once the requirement for the limiting amino acid is met there will be no further change in the indicator oxidation. The IAAO method has been systematically applied to determine most IDAA requirements in adults. The estimates are comparable to the values obtained using the more elaborate 24h-indicator amino acid oxidation and balance (24h-IAAO/IAAB) model. Due to its non-invasive nature the IAAO method has also been used to determine requirements for amino acids in neonates, children and in disease. The IAAO model has recently been applied to determine total protein requirements in humans. The IAAO method is rapid, reliable and has been used to determine amino acid requirements in different species, across the life cycle and in disease. The recent application of IAAO to determine protein requirements in humans is novel and has significant implications for dietary protein intake recommendations globally.

scholarly journals Lysine requirements of healthy adult Indian subjects receiving long-term feeding, measured with a 24-h indicator amino acid oxidation and balance technique

2002 ◽  
Vol 76 (2) ◽  
pp. 404-412 ◽  
Author(s):  
Anura V Kurpad ◽  
Meredith M Regan ◽  
Tony Raj ◽  
Antoine El-Khoury ◽  
Rebecca Kuriyan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Healthy Adult ◽  
Acid Oxidation ◽  
Amino Acid Oxidation ◽  
Balance Technique
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