An Evaluation of Protein Intake for Metabolic Demands and the Quality of Dietary Protein in Rats Using an Indicator Amino Acid Oxidation Method

ABSTRACT Background Lysine rich foods such as milk and legumes serve as important food additions to the lysine deficient cereal-based diets of vegetarian populations in low- and middle-income countries (LMICs) to alleviate the risk of quality corrected dietary protein inadequacy. Dietary protein quality can be determined by estimating the metabolic availability (MA) of lysine. Objectives The study aimed to estimate the MA of lysine in spray-dried cow milk powder (SMP), heat-treated spray-dried cow milk powder (HSMP), and a habitually consumed cereal-legume based vegetarian meal (VM), using the indicator amino acid oxidation (IAAO) slope-ratio method. Methods The MA of lysine in SMP, HSMP, and VM was estimated in 7 healthy young men aged 19–24 y with BMI of 21.5 ± 0.5 kg/m2 in a repeated measures design. The IAAO response slopes with 2 graded lysine intakes (10.5 and 15.0 mg·kg−1·d−1) from the SMP and VM were compared with the response slope generated with 3 graded crystalline lysine intakes (6.0, 10.5, and 15.0 mg·kg−1·d−1) at the subrequirement level. To produce HSMP, pasteurized cow milk was heat treated and spray dried. The MA of lysine in HSMP was tested at a single level of lysine intake (15 mg·kg−1·d−1). A total of 8 IAAO experiments were conducted on each participant in randomized order. The IAAO slopes were estimated using a linear mixed-effect regression model. Results The MA of lysine in SMP, HSMP, and VM was 91.9%, 69.9%, and 86.6% respectively. Conclusions Heat treatment reduced the MA of lysine by 22% in HSMP compared with SMP in healthy Indian adults. The lysine MA estimates can be used to optimize lysine limited cereal-based diets, with the addition of appropriately processed legumes and milk powder, to meet the protein requirement. This trial was registered at Clinical Trials Registry of India (http://ctri.nic.in) as CTRI/2019/08/020568.

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

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00174.2018 ◽

2019 ◽

Vol 316 (5) ◽

pp. E741-E748 ◽

Cited By ~ 6

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.

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The Indicator Amino Acid Oxidation Method with the Use of l-[1- 13 C]Leucine Suggests a Higher than Currently Recommended Protein Requirement in Children with Phenylketonuria

Journal of Nutrition ◽

10.3945/jn.116.240218 ◽

2017 ◽

Vol 147 (2) ◽

pp. 211-217 ◽

Cited By ~ 1

Author(s):

Abrar Turki ◽

Keiko Ueda ◽

Barbara Cheng ◽

Alette Giezen ◽

Ramona Salvarinova ◽

...

Keyword(s):

Amino Acid ◽

Acid Oxidation ◽

Protein Requirement ◽

Oxidation Method ◽

Amino Acid Oxidation

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Diurnal response in endogenous amino acid oxidation of meal-fed rats

Biochemical Journal ◽

10.1042/bj1900663 ◽

1980 ◽

Vol 190 (3) ◽

pp. 663-671 ◽

Cited By ~ 7

Author(s):

R W Wannemacher ◽

R E Dinterman

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Dietary Protein ◽

Normal Diet ◽

Acid Oxidation ◽

Body Protein ◽

Amino Acid Oxidation ◽

Collagen Protein ◽

Meal Feeding ◽

Endogenous Amino Acid

A model has been developed to measure the effects of dietary protein on daily fluctuations in the rate of endogenous amino acid oxidation in meal-fed and starved rats. In addition, N tau-methylhistidine and hydroxyproline were utilized to determine changes in the rate of degradation of myofibrillar and collagen proteins. In rats meal-fed a normal diet of 18% (w/w) casein, a diurnal response was observed in rate of oxidation of radioactive amino acids contained in endogenous labelled body protein, with a nadir 16—20 h and maximum 4—8 h after beginning the feeding. This observation in part may be related to alterations in flux of amino acids from non-hepatic tissues to site of oxidation in liver, as well as alterations in rates of amino acid oxidation after a protein meal. When meal-fed a 70% protein diet, the maximal rates of endogenous amino acid oxidation were significantly increased by 4—8 h after meal-feeding, with no change in fractional rates of degradation of myofibrillar- or collagen-protein breakdown. This could suggest increases in activities of enzymes involved in amino acid oxidation, in rats meal-fed 70% compared with 18% dietary protein. In contrast, meal-feeding of a protein-free diet muted the diurnal response in the rate of oxidation of endogenously labelled amino acids, which correlated with a decrease in the fractional rate of degradation of myofibrillar or collagen protein. Thus dietary protein is apparently responsible for the observed diurnal rhythm rhythms in the rate of amino acid oxidation, whereas carbohydrates tend to mute the response.

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Tryptophan Requirement in School-Age Children Determined by the Indicator Amino Acid Oxidation Method is Similar to Current Recommendations

Journal of Nutrition ◽

10.1093/jn/nxy250 ◽

2019 ◽

Vol 149 (2) ◽

pp. 280-285 ◽

Cited By ~ 1

Author(s):

Abeer Al-mokbel ◽

Glenda Courtney-Martin ◽

Rajavel Elango ◽

Ronald O Ball ◽

Paul B Pencharz ◽

...

Keyword(s):

Amino Acid ◽

Protein Intake ◽

School Age Children ◽

Acid Mixture ◽

Acid Oxidation ◽

School Age ◽

Mixed Effect ◽

Effect Change ◽

Amino Acid Oxidation ◽

The Mean

ABSTRACT Background The requirement for dietary tryptophan in school-age children has never been empirically derived. Objective The objective of our study was to determine the tryptophan requirement of school-age children using the indicator amino acid oxidation technique. Methods Volunteer healthy school-age children, between 8 and 12 y, were enrolled and the oxidation of l-[13C]-phenylalanine to 13CO2 measured in response to graded intakes of dietary tryptophan. Seven children (3 boys, 4 girls) participated in the study and received randomly assigned tryptophan intakes ranging from 0.5 to 9.75 mg.kg-1.d-1 for a total of 36 studies. The diets provided energy at 1.5 times each subject's resting energy expenditure and were isocaloric. Protein was provided as an amino acid mixture on the basis of the egg protein pattern, and phenylalanine and tyrosine were maintained constant across the protein intake concentrations at 25 and 40 mg.kg−1.d−1. All subjects were adapted for 2 d before the study day to a protein intake of 1.5 g.kg−1.d−1. The mean tryptophan requirement was determined by applying a mixed-effect change-point regression analysis to F13CO2 (label tracer oxidation in 13CO2 breath) which identified a breakpoint in the F13CO2 in response to graded amounts of tryptophan. Results The mean [estimated average requirement (EAR)] and upper 95% CI, (approximating the RDA) of tryptophan requirements were estimated to be 4.7 and 6.1 mg.kg−1.d−1, respectively. Conclusion Our results are similar to the current recommended EAR and RDA of 5 and 6 mg.kg−1.d−1 for healthy growing children based on the factorial calculation. Clinical Trials Registration No. NCT02018588.

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Protein Requirements Are Elevated in Endurance Athletes according to the Indicator Amino Acid Oxidation Method

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000485023.08899.ef ◽

2016 ◽

Vol 48 ◽

pp. 5-6 ◽

Cited By ~ 1

Author(s):

Hiroyuki Kato ◽

Katsuya Suzuki ◽

Makoto Bannai ◽

Daniel R. Moore

Keyword(s):

Amino Acid ◽

Endurance Athletes ◽

Acid Oxidation ◽

Oxidation Method ◽

Amino Acid Oxidation ◽

Protein Requirements

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Dietary Protein Requirement of Men >65 Years Old Determined by the Indicator Amino Acid Oxidation Technique Is Higher than the Current Estimated Average Requirement

Journal of Nutrition ◽

10.3945/jn.115.225631 ◽

2015 ◽

Vol 146 (4) ◽

pp. 681-687 ◽

Cited By ~ 28

Author(s):

Mahroukh Rafii ◽

Karen Chapman ◽

Rajavel Elango ◽

Wayne W Campbell ◽

Ronald O Ball ◽

...

Keyword(s):

Amino Acid ◽

Dietary Protein ◽

Acid Oxidation ◽

Protein Requirement ◽

Amino Acid Oxidation

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Protein requirements and the indicator amino acid oxidation method

American Journal of Clinical Nutrition ◽

10.3945/ajcn.112.036830 ◽

2012 ◽

Vol 95 (6) ◽

pp. 1498-1501 ◽

Cited By ~ 18

Author(s):

D Joe Millward ◽

Alan A Jackson

Keyword(s):

Amino Acid ◽

Acid Oxidation ◽

Oxidation Method ◽

Amino Acid Oxidation ◽

Protein Requirements

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Protein Intake to Maximize Whole-Body Anabolism during Postexercise Recovery in Resistance-Trained Men with High Habitual Intakes is Severalfold Greater than the Current Recommended Dietary Allowance

Journal of Nutrition ◽

10.1093/jn/nxz249 ◽

2019 ◽

Cited By ~ 4

Author(s):

Michael Mazzulla ◽

Sidney Abou Sawan ◽

Eric Williamson ◽

Sarkis J Hannaian ◽

Kimberly A Volterman ◽

...

Keyword(s):

Protein Synthesis ◽

Steady State ◽

Amino Acid ◽

Resistance Exercise ◽

Protein Intake ◽

Whole Body ◽

Total Amino Acid ◽

Acid Oxidation ◽

Amino Acid Oxidation ◽

Habitual Protein Intake

ABSTRACT Background Dietary protein supports resistance exercise–induced anabolism primarily via the stimulation of protein synthesis rates. The indicator amino acid oxidation (IAAO) technique provides a noninvasive estimate of the protein intake that maximizes whole-body protein synthesis rates and net protein balance. Objective We utilized IAAO to determine the maximal anabolic response to postexercise protein ingestion in resistance-trained men. Methods Seven resistance-trained men (mean ± SD age 24 ± 3 y; weight 80 ± 9 kg; 11 ± 5% body fat; habitual protein intake 2.3 ± 0.6 g·kg−1·d−1) performed a bout of whole-body resistance exercise prior to ingesting hourly mixed meals, which provided a variable amount of protein (0.20–3.00 g·kg−1·d−1) as crystalline amino acids modeled after egg protein. Steady-state protein kinetics were modeled with oral l-[1-13C]-phenylalanine. Breath and urine samples were taken at isotopic steady state to determine phenylalanine flux (PheRa), phenylalanine excretion (F13CO2; reciprocal of protein synthesis), and net balance (protein synthesis − PheRa). Total amino acid oxidation was estimated from the ratio of urinary urea and creatinine. Results Mixed model biphasic linear regression revealed a plateau in F13CO2 (mean: 2.00; 95% CI: 1.62, 2.38 g protein·kg−1·d−1) (r2 = 0.64; P ˂ 0.01) and in net balance (mean: 2.01; 95% CI: 1.44, 2.57 g protein·kg−1·d−1) (r2 = 0.63; P ˂ 0.01). Ratios of urinary urea and creatinine concentrations increased linearly (r = 0.84; P ˂ 0.01) across the range of protein intakes. Conclusions A breakpoint protein intake of ∼2.0 g·kg−1·d−1, which maximized whole-body anabolism in resistance-trained men after exercise, is greater than previous IAAO-derived estimates for nonexercising men and is at the upper range of current general protein recommendations for athletes. The capacity to enhance whole-body net balance may be greater than previously suggested to maximize muscle protein synthesis in resistance-trained athletes accustomed to a high habitual protein intake. This trial was registered at clinicaltrials.gov as NCT03696264.

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