Urine Metabolite Profiles after the Consumption of a Low- and a High-Digestible Protein Meal, and Comparison of Urine Normalization Techniques.

In the context of dietary transition toward plant proteins, it is necessary to ensure protein security in populations. It would thus be of interest to identify biomarkers of altered protein digestibility in populations. We examined the association between urinary metabolites and the acute intake of low- or highly digestible protein in healthy volunteers. The urine samples were collected before and 9 h after the ingestion of a meal containing either no protein, zein (low-digestible) or whey protein isolate (highly digestible). The liquid chromatography-high resolution mass spectrometry metabolomics approach was used for the profiling of the urinary metabolites. For the standardization of metabolomics data sets, osmolality-based, standard normal variates (SNV) and probabilistic quotient normalization (PQN) techniques were used. The ANOVA-based factorial method, AComDim_ICA, was used for chemometrics analysis. The osmolality adjustment has a beneficial effect and the subsequent mathematical normalization improves the chemometric analysis further. Some changes in the urinary metabolomes were observed 9 h after the meal in the three groups. However, there was no difference in the urine metabolome between groups. No biomarker of protein digestibility can be identified after the ingestion of a single meal, even when marked differences in the digestion efficiency of protein have been observed.

Modeling net energy requirements of 2 to 3-week-old Cherry Valley ducks.

OBJECTIVE: A total of three hundred unsexed ducks were utilized to estimate net energy requirements of maintenance (NEm) and weight gain (NEg) for 2 to 3-week-old Cherry Valley ducks and to establish a model equation to predict NE requirements using the factorial method. METHODS: To determine the apparent metabolizable energy (AME) of the diet, fifty 7-day-old ducks at approximately equal body weights (BWs) were randomly assigned into five groups that were fed at different levels (ad libitum, 85%, 75%, 65%, and 55% of ad libitum intake), and the endogenous acid-insoluble ash as indigestible marker. The two hundred and fifty 7-day-old ducks were used for a comparative slaughter experiment. At the beginning of the experiment, ten ducks were sacrificed to determine the initial body composition and energy content. The remaining ducks were randomly assigned into five groups (same as metabolic experiment). Ducks of the ad libitum group were slaughtered at 14 and 21-dayold. At the end of the experiment, two ducks were selected from each replicate and slaughtered to determine the body composition and energy content. RESULTS: The results of the metabolizable experiment showed AME values of 13.43 to 13.77 MJ/kg for ducks at different feed intakes. The results of the comparative slaughter experiment showed the NEm value for 2 to 3-week-old Cherry Valley ducks was 549.54 kJ/kg of BW0.75/d, and the NEg value was 10.41 kJ/g. The deposition efficiency values of fat (Kf) and crude protein (Kp) were 0.96 and 0.60, respectively, and the values of efficiency of energy utilization (Kg) and maintenance efficiency (Km) were 0.75 and 0.88, respectively. CONCLUSION: The equation for the prediction of NE requirements for 2 to 3-week-old Cherry Valley ducks was the following: NE = 549.54 BW0.75+10.41 ΔW, where ΔW is the weight gain (g).

Models for predicting protein requirements for meat quail.

Three experiments were carried out to determine the crude protein requirements for maintenance (CPm) and weight gain (CPg) of meat quail and to develop protein-requirement prediction models. Experiment 1 was conducted to determine CPm by the nitrogen-balance technique. The regression of nitrogen balance on nitrogen intake revealed a CPm requirement of 2.94 g/kg0.75 /day. Experiment 2 was aimed at determining CPm by the comparative-slaughter technique. Retained nitrogen (RN) and nitrogen intake (NI) were quantified considering the metabolic weight of the birds. The linear regression of RN on NI provided a CPm estimate of 6.63 g/kg0.75 /day. Experiment 3 was conducted to determine CPg. The regression of body nitrogen from the carcasses on fasted body weight revealed CPg estimates of 407.68 (0-7 days), 501.76 (8-14 days), 470.40 (0-14 days), 517.44 (15-21 days), 627.20 (22-28 days), 423.36 (29-35 days), and 517.44 mg/g (15-35 days). The protein-requirement prediction models developed for meat quail aged 0-7, 8-14, 0-14, 15-21, 22-28, 29-35, and 15-35 days were CP = 2.94.W0.75  + 0.408.G; CP = 2.94.W0.75  + 0.502.G; CP = 2.94.W0.75  + 0.470.G; CP = 2.94.W0.75  + 0,517.G; CP = 2.94.W0.75  + 0.627.G; CP = 2.94.W0.75  + 0.423.G; CP = 2.94.W0.75  + 0.517.G, respectively, where: W0.75  =  metabolic weight (kg), and G =  daily weight gain (g).

Investigating the Essentiality and Requirements of Iron from the Ancient to the Present.

This review discusses the development of studies that evaluated the essentiality and requirements of iron from the ancient to the present. The therapeutic effects of iron compounds were recognized by the ancient Greeks and Romans. The earliest recognition of the essentiality of iron was stated by Paracelsus, a distinguished physician alchemist, in the sixteenth century. Iron was included in the earliest nutritional standard prepared for the Royal Army by E. A. Parkes, the first professor of hygiene. The League of Nations Health Organisation determined average iron requirements based on literature review. In the first US Recommended Dietary Allowances (RDA), the RDA of iron was determined from the results of iron balance studies. In the current Dietary Reference Intakes, iron requirements were determined based on the factorial method with the aid of Monte Carlo simulation for combining basal and menstrual iron losses. Population data analysis is a recently developed alternative that does not use the pre-estimated iron absorption rate and requires the prevalence of inadequacy instead. Population data analysis uses the convolution integral for combining basal and menstrual iron losses to ensure the required accuracy. This review also provides new estimates of hair and nail iron losses.

Estimation of Energy Expenditure among Malaysian Young Adults: A Pilot Study Comparing Heart Rate Monitoring (HRM) Method and Activity Diary (AD) Method

Introduction: Accurate yet inexpensive methods for measuring free-living energy expenditure (EE) are much needed. The aim of this study was to determine the feasibility of heart-rate monitoring method (HRM) in measuring EE as compared to the established activity diary (AD) were used simultaneously in 34 young adults (18 females, 16 males, mean age 21.5 ± 1.5 years). Estimates of the EE from HRM were based on individually measured and published energy cost of various activities. Total daily energy expenditure (TDEE) and its components (EE during sleep, during rest and during physical activity) were compared using Student paired-t tests. Results: TDEE from HRM method averaged 8.17 ± 2.00 MJ/day compared to 8.50 ± 1.28 MJ/day from AD method. Although large intra-individual differences were found (ranging from -36.9% to 47.4%), there was no significant difference between the two methods (mean difference -3.6 ± 19.4%). The limits of agreement (mean ± 2SD) were -3.77 and 3.11 MJ/day. There were no significant differences for any of the TDEE components between the two methods, except for EE during sleep (p<0.05). Conclusion: HRM method was found to be a feasible method for assessment of EE, and was comparable to AD for group assessment of TDEE and its components

Determinacion dll gasto energetico (ge) por el etodo factorial en patinadores Cubanos de velocidad / Determinatio of energetic waste by the factorial method in high velocity skiiers

Se estudiaron 4 varones y 5 hembras del equipo cubano de patinaje velocidad para estimar su estado nutricional, GE y establecer recomendaciones nutricionales. U n microciclo tipo de las etapas de preparación general (G) y especial (E) constituyó el marco de medición. El GE se determinó mediante método factorial. Se realizó estadística inferencial para considerar diferencias entre variables por sexo y etapas para p ≤ 0,05. Para calcular las recomendaciones nutricionales se estimó el NAF. Se observaron características morfológicas similares a las reportadas en patinadores colombianos, así como un IMC adecuado. El GE por entrenamiento fue significativamente diferente en las dos etapas y el GET fue superior en la de PG. Energéticamente, se observó tendencia a valores superiores en los hombres en todos los indicadores, excepto para las actividades discrecionales durante la etapa de PE y el NAF de ambas y las recomendaciones dependieron de la etapa de preparación de estos patinadores.

Four and five female and male speed roller skaters of Cuban team were studied for nutritional status and energy cost estimation even as energy recommendations. A microcycle type of general (G) and special (S) training phases was the frame for measuring. EC was determined by factorial method. Inferential statistics for estimating differences between variables by sex and phases of training was for p ≤ 0,05. In order to make energy recommendations a PAL was also estimated. Morphological characteristics were similar to those reported in Colombian roller skaters and BMI was adequate. Sport training energy cost was significantly different in both phases and TEC was higher in G. It was observed that male skaters showed a trend to have higher values for all variables with the exception of discretionary activities in S and PAL for both phases. Energy recommendations depended on training phase of speed roller skaters.