Body Protein Mass Research Articles

Body composition of male and female Chilean powerlifters of varying body mass

Abstract Aim: To examine body composition of Chilean powerlifters according to body mass and sex. Methods: Fifty-six male and female powerlifters were recruited from one national competition. Aside from the official weight categories, males were classified as the lightweight, middleweight, and heavyweight classes. Similarly, females were classified as lightweight and middle-heavyweight classes. Nineteen anthropometric measures were assessed, with lean mass as the main outcome. A one-way ANOVA was used to compare groups. Results: Male lightweight class lifted less (p<0.01) total load (417±30.9 kg) compared to heavier male classes (524±66.7 kg, middleweight; 581±131 kg, heavyweight), and female classes lifted less (p<0.01) total load (221±33.8 kg, lightweight; 254±48.3 kg, middleweight-heavyweight) compared to all male classes. Regarding lean-mass in trunk, arms and legs, total body protein, water, and mineral mass, all male groups had greater (p<0.01) values than the groups of females, while lightweight males had lower (p<0.01) values than the rest of male groups, and heavyweight males had greater (p<0.01) values than the total sample of males (except for legs lean mass, and total bone mineral content). In females, no significant differences were observed between classes, or in total load lifted or in body composition. Conclusion: Heavier male lifters had significantly greater lean mass than lighter athletes. Therefore, powerlifting performance was affected by anthropometric measures, as corroborated by 1-RM scores. However, there was a general lack of differences in body composition between female weight classes, and, as a result, a lack of differences in 1RM performance.

Alleviation of Metabolic Syndrome with Dietary Egg White Protein.

Abdominal fat accumulation causes metabolic syndrome, which is a cluster of metabolic abnormalities such as dyslipidemia, glucose intolerance, insulin resistance or hyperinsulinemia, and hypertension, leading to the development of diabetes and cardiovascular disease. Diets are known to contribute to the development or prevention of metabolic syndrome. Several studies have reported that the quality of dietary proteins may be an important modulator of the risk of this syndrome. We investigated the effects of consuming egg white protein (EWP) or lactic-fermented egg white (LE), an easy-to-consume form of egg white, on the development of metabolic syndrome in animal models and humans. In comparison with casein, dietary EWP decreased lymphatic lipid transport in thoracic lymph duct-cannulated rats. In an in vitro experiment, EWP pepsin hydrolysate decreased the cholesterol micellar solubility and cholesterol transfer rate from micelles to oil phase, and increased water-holding capacity, settling volume in water, and relative viscosity compared with casein pepsin hydrolysate. The daily consumption of LE for 8 weeks reduced serum total cholesterol and LDL cholesterol levels in men with mild hypercholesterolemia. Furthermore, dietary EWP reduced the body fat mass of rats by increasing the body protein mass and accelerating hepatic β-oxidation. The daily consumption of LE for 12 weeks reduced the visceral fat area and improved the ratio of the visceral to subcutaneous fat area. Taken together, these results indicated that dietary EWP and LE would be useful for preventing or alleviating metabolic syndrome.

Pre‐basic molt, feather quality, and modulation of the adrenocortical response to stress in two populations of rufous‐collared sparrows Zonotrichia capensis

Molt is an energetically expensive process in which birds may allocate 25% or more of their body protein mass to the production of new feathers. Stressful events can interfere with feather growth via the adrenal hormone corticosterone, which is released in response to environmental stress. Corticosterone release, in turn, regulates gluconeogenesis which could directly inhibit protein synthesis and deposition during molt when feathers are growing, which potentially could reduce feather quality dramatically. Thus, many species suppress the adrenocortical stress response, and therefore maintain lower corticosterone levels during molt. In this study we assessed the relationship between plasma corticosterone levels and feather quality in rufous‐collared sparrow inhabiting the valleys of the Atacama Desert – one of the most stable and aseasonal environments in the world, and in the semiarid and seasonal Fray Jorge National Park in the north of Chile. We tested two hypotheses; 1) feather quality is positively related to the amount of corticosterone suppression during molt, relative to corticosterone levels during other life history stages; and, 2) feather quality is negatively related to the absolute levels of corticosterone. We found negative associations between corticosterone levels and feather quality. However, these effects were stronger in the Atacama Desert where birds showed minimal corticosterone suppression and overall low feather quality. Although we found better feather quality in Fray Jorge, corticosterone suppression in these birds was relatively low in comparison with other species inhabiting higher latitudes. It is possible that birds in a highly variable environment face a stronger trade‐off between feather quality and the stress‐response. Our results suggest that the strength of the trade‐off between feather quality and corticosterone levels could be dependent on energetic demands, seasonality, and unpredictable events.

Estimated energy requirements increase across pregnancy in healthy women with dichorionic twins

Estimated energy requirement (EER) has not been defined for twin pregnancy. This study was designed to determine the EER of healthy women with dichorionic-diamniotic (DCDA) twin pregnancies. We aimed to estimate energy deposition from changes in maternal body protein and fat; to measure resting energy expenditure (REE), physical activity level (PAL), and total energy expenditure (TEE) throughout pregnancy and postpartum; and to define the EER based on the sum of TEE and energy deposition for twin gestation. This is a prospective study of 20 women with DCDA twin gestations. Maternal EER, energy deposition, REE, TEE, and PAL were obtained during the first, second, and third trimesters of pregnancy and immediately postpartum. A mixed-effects linear regression model for repeated measures with random intercept was used to test for the effects of BMI groups and time. Gains in total body protein (mean±SD: 2.1±0.7 kg) and fat mass (5.9±2.8 kg) resulted in total energy deposition of 67,042±25,586 kcal between 0 and 30-32 weeks of gestation. REE increased 26% from 1392±162 to 1752±172 kcal/d across the 3 trimesters, whereas TEE increased 17% from 2141±283 to 2515±337 kcal/d. Physical activity decreased steadily throughout pregnancy. Reductions in physical activity did not compensate for the rise in REE and energy deposition, thus requiring an increase in dietary energy intake as pregnancy progressed. EER increased 29% from 2257±325 kcal/d in the first trimester to 2941±407 kcal/d in the second trimester, and stayed consistent at 2906±350 kcal/d in the third trimester. Increased energy intake, on average ∼700 kcal/d in the second and third trimesters when compared with the first trimester, is required to support gestational weight gain and the rise in energy expenditure of DCDA twin pregnancies.

Insulin-like growth factor-1 as a nutritional monitoring factor in patients with chronic intestinal failure

Nutritional monitoring plays an important role in optimizing nutritional support inpatients with chronic intestinal failure (CIF) receiving long-term supplementation. Unlike initial nutritional assessment, however, there are no recommended guidelines for establishing a nutritional monitoring index. This study is to evaluate the suitability of insulin-like growth factor-1 (IGF-1) as a nutritional monitoring factor in CIF patients. We retrospectively analyzed the correlation between serum nutritional indicators, including IGF-1 levels, and nutritional assessment, nutritional monitoring, and lean body mass in 197 patients with CIF. The mean age of the 197 enrolled patients was 47.22±18.87 years old and; the mean BMI was 16.83±3.31. The mean NRS-2002 score was 3.49±0.83; and moreover, 76.3% of the patients were malnourished. The median length of hospital stay in hospital (LOS) was 18.5 days. IGF-1 was positively correlated with body mass index, hemoglobin, albumin, pre-albumin, retinol-binding protein (RBP), transferrin, serum creatinine (Scr) and cholesterol (p<0.05 for all). Testing performed over 3 weeks post-admission showed that significantly different weekly changes were observed only in IGF-1, RBP, and Scr during the period of nutritional support (p<0.05 for each). Multivariate linear regression analysis showed that IGF-1 and body mass index were independent factors influencing fat-free mass, skeletal muscle mass, and body protein mass (p<0.05 for each). IGF-1 is suitable for monitoring short-term changes in the nutritional status in CIF patients. This may be attributed to its shorter half-life, greater sensitivity, and better correlation with lean body mass. ClinicalTrials.gov number, NCT03277014.

Supplementation of suckling rats with cow's milk induces hyperphagia and higher visceral adiposity in females at adulthood, but not in males

In humans, complementary feeding should be started after 6 months-old; the introduction of any food or water before this time is considered early weaning, which is associated with health problems in adulthood. Cow's milk is a common food introduced to children less than 6 months that has inadequate nutritional composition mainly due to a worse casein: whey protein ratio compared to human milk. We hypothesized that suckling rats fed with cow's milk, rich in bioactive peptides, develop further metabolic dysfunctions. From postnatal day (PN) 14 to 20, Wistar rat pups were divided into 3 groups: rat milk (RM) – pups received rat milk orally in a syringe; cow's milk (CM), pups received cow's milk; CM with high protein (CM-H), CM with twice protein amount of rat milk. Pups were killed on PN21 and PN180. At PN21, CM males had lower visceral fat mass compared with other groups. Serum corticosterone was higher in CM-H males, despite no change in glucocorticoid metabolism in liver and visceral fat. At PN180, CM and CM-H females had greater fat depots and hyperphagia, although no alteration in leptinemia and leptin signaling in hypothalamus. CM-H females had a trend of hypoinsulinemia and significant decrease in HOMA-β, suggesting lower insulin secretion. Males from CM-H group had only lower total body protein mass. CM males had hypercorticosteronemia associated with lower expression of 11βHDS1 in visceral fat. In conclusion, early introduction of cow's milk in neonate rats leads to gender-dependent differences in metabolic and endocrine parameters in the short- and long-term.

Dietary egg-white protein increases body protein mass and reduces body fat mass through an acceleration of hepatic β-oxidation in rats.

Egg-white protein (EWP) is known to reduce lymphatic TAG transport in rats. In this study, we investigated the effects of dietary EWP on body fat mass. Male rats, 4 weeks old, were fed diets containing either 20 % EWP or casein for 28 d. Carcass protein levels and gastrocnemius leg muscle weights in the EWP group were significantly higher than those in the casein group. In addition, carcass TAG levels and abdominal fat weights in the EWP group were significantly lower than those in the casein group; adipocyte size in abdominal fat in the EWP group was smaller than that in the casein group. To identify the involvement of dietary fat levels in the rats, one of two fat levels (5 or 10 %) was added to their diet along with the different protein sources (EWP and casein). Abdominal fat weight and serum and hepatic TAG levels were significantly lower in the EWP group than in the casein group. Moreover, significantly higher values of enzymatic activity related to β-oxidation in the liver were observed in the EWP group compared with the casein group. Finally, abdominal fat weight reduction in the EWP group with the 10 % fat diet was lower than that in the EWP group with the 5 % fat diet. In conclusion, our results indicate that, in addition to the inhibition of dietary TAG absorption reported previously, dietary EWP reduces body fat mass in rats through an increase of body protein mass and the acceleration of β-oxidation in the liver.

Multivariate Analysis of Effectiveness of Lifestyle Modification Programs in Treatment for Obesity

This study is aimed to compare the outcomes of life-style interventions on the anthropometric and body composition parameters in obese adult population. In this study, hundred and sixty-three obese participants, 108 female and 55 male adults with abdominal obesity were included. All participants had a body mass index over 30. During the duration of the weight loss program they were randomized in two groups (A & B). Group A underwent the weight loss program which included dietary reduction approach. Group B, in parallel, underwent the weight program which included dietary reduction along with exercise. On the start and after studied intervals (three and twelve months) following parameters were recorded: body height (BH), body weight (BW), body mass index, waist-hip ratio (WHR), fat mass (FM), percentage of body fat (%BF), protein mass (PM), mineral mass (MM) and total body water (TBW). The principal component analysis was used to emphasize variation and bring out strong patterns in the dataset. Three months of life-style change program resulted with favourable effect on anthropometric parameters and body composition of both genders. Significant decreases in all monitored parameters were observed after both types of intervention with particular emphasis on changes of the body fat mass and body weight. Moreover, the measured parameters after 12 months participation in the weight loss programs showed a significant positive trend of losing body weight and especially body fat mass. BM and BF decrease was even more significant in the group that has had included exercising in the life style change.

Sagittal spinal alignment in asymptomatic patients over 30years old in the Korean population.

We aim to provide sagittal and pelvic parameters according to different age groups in an asymptomatic population all over 30years old and to investigate the possible causes of changes in these parameters. Whole-spine, standing lateral radiographs were taken in 128 asymptomatic Korean people over 30years old. The spinal parameters (the total thoracic kyphosis (TTK), maximal lumbar lordosis (MLL), total lumbar lordosis (TLL), lower lumbar lordosis (LLL), thoracolumbar junctional angle (TLJA), and lumbar inclination (LI)), pelvic parameters (pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT)), and spinal balance parameters (spinal balance, sacropelvic balance, and spinopelvic balance) were measured. The body mass index, body protein mass, waist line, skeletal muscle mass, and body fat mass were also measured for potential causes. TTK and TLJA were significantly increased in the group over 70years of age compared to the other age groups (p = 0.0002, <0.001). TLL was significantly decreased in the group over 70years of age (p = 0.002), whereas the PI values were similar to PI even in over 70-year age group. LLL did not differ in the group over 70years of age (p = 0.29), gradually increasing with an increase in age. SS was significantly decreased and PT was significantly increased in the group over 70years of age as compared to the other age groups (p = 0.049, 0.049, respectively). PI was similar in all age groups (p = 0.75). Spinal balance was significantly decreased in the group over 70years of age (p = <0.0001). PT was significantly associated with body protein mass and skeletal muscle mass (p = 0.01, 0.001, respectively). Body protein mass and skeletal muscle mass were significantly lower in the group over 70years of age (p = 0.02, 0.02) and were possible causes. Several sagittal and pelvic parameters are different in asymptomatic adults over 70years of age. Decreased body protein mass and skeletal muscle mass are possible causes of these changes.

Combining intra-dialytic exercise and nutritional supplementation in malnourished older haemodialysis patients: Towards better quality of life and autonomy.

Protein-energy wasting (PEW), defined as a loss of body protein mass and fuel reserves, is a powerful predictor of adverse outcomes in haemodialysis (HD) patients. Robust arguments suggest that intra-dialytic exercise, combined with oral/parenteral nutrition, enhances the effect of nutritional interventions in HD patients. This pilot randomized controlled trial investigated the feasibility and the effects of a 6 month intra-dialytic cycling program combined to a nutritional support on PEW, physical functioning (gait, balance, muscle strength) and quality of life (QoL) in older HD patients (mean age 69.7 ± 14.2 years).Twenty-one patients fulfilling diagnostic criteria of PEW were randomly assigned to Nutrition-Exercise group (GN-Ex , n = 10) or Nutrition group (GN , n = 11). Both groups received nutritional supplements in order to reach recommended protein and energy intake goals. In addition GN-Ex completed a cycling program. No significant difference between groups was found in the number of patients having reached remission of PEW. Likewise, no change was observed in serum-albumin, -prealbumin, C-reactive protein, body mass index, lean- and fat-tissue index, or quadriceps force. Interestingly, we found positive effects of exercise on physical function and QoL for the GN-Ex , as evidenced by a significant improvement in the 6-min walk test (+22%), the absence of decline in balance (unlike the GN ), and a noteworthy increase in QoL (+53%). Combining intra-dialytic exercise and nutrition in HD patients is feasible, and well accepted, improves physical function and QoL but it appears not to have the potential to reverse PEW.

Ramadan Fasting Decreases Body Fat but Not Protein Mass.

Background:Many studies have shown various results regarding the effects of Ramadan fasting on weight and body composition in healthy individuals. Objectives: This study aimed to evaluate the effect of Ramadan fasting on body composition in healthy Indonesian medical staff.Objectives:In this study, we examined the influence of Ramadan fasting on body composition in healthy medical staff.Patients and Methods:The longitudinal study was performed during and after Ramadan fasting in 2013 (August to October). Fourty-three medical staff members (physicians, nurses and nutritionists) at the Internal Medicine Ward of the Dr. Cipto Mangunkusumo General Hospital were measured to compare their calorie intake, weight, body mass index, waist-to-hip ratio (WHR), and body composition, including body fat, protein, minerals and water, on the first and 28th days of Ramadan and also 4-5 weeks after Ramadan fasting. Measurements were obtained for all 43 subjects on the 28th day of Ramadan, but they were obtained for only 25 subjects 4 - 5 weeks after Ramadan.Results:By the 28th day of Ramadan, it was found that the body weight, BMI, body fat, water and mineral measures had decreased significantly (-0.874 ± 0.859 kg, P < 0.001; -0.36 ± 0.371 kg/m2, P < 0.001; -0.484 ± 0.597 kg, P < 0.001; -0.293 ± 0.486 kg, P = 0.001; -0.054 ± 0.059 kg, P < 0.001, respectively). Protein body mass and calorie intake did not significantly change (-0.049 ± 0.170 kg, P = 0.561; 12.94 ± 760.608 Kcal, P = 0.082 respectively). By 4 - 5 weeks after Ramadan, body weight and composition had returned to the same levels as on the first day of Ramadan.Conclusions:Ramadan fasting resulted in weight loss even it was only a temporary effect, as the weight was quickly regained within one month after fasting. The catabolism catabolic state, which is related to protein loss, was not triggered during Ramadan fasting. Further research is needed to evaluate the effects of weight loss during Ramadan fasting in healthy individuals.

Precision feeding can significantly reduce lysine intake and nitrogen excretion without compromising the performance of growing pigs

This study was developed to assess the impact on performance, nutrient balance, serum parameters and feeding costs resulting from the switching of conventional to precision-feeding programs for growing–finishing pigs. A total of 70 pigs (30.4±2.2 kg BW) were used in a performance trial (84 days). The five treatments used in this experiment were a three-phase group-feeding program (control) obtained with fixed blending proportions of feeds A (high nutrient density) and B (low nutrient density); against four individual daily-phase feeding programs in which the blending proportions of feeds A and B were updated daily to meet 110%, 100%, 90% or 80% of the lysine requirements estimated using a mathematical model. Feed intake was recorded automatically by a computerized device in the feeders, and the pigs were weighed weekly during the project. Body composition traits were estimated by scanning with an ultrasound device and densitometer every 28 days. Nitrogen and phosphorus excretions were calculated by the difference between retention (obtained from densitometer measurements) and intake. Feeding costs were assessed using 2013 ingredient cost data. Feed intake, feed efficiency, back fat thickness, body fat mass and serum contents of total protein and phosphorus were similar among treatments. Feeding pigs in a daily-basis program providing 110%, 100% or 90% of the estimated individual lysine requirements also did not influence BW, body protein mass, weight gain and nitrogen retention in comparison with the animals in the group-feeding program. However, feeding pigs individually with diets tailored to match 100% of nutrient requirements made it possible to reduce (P<0.05) digestible lysine intake by 26%, estimated nitrogen excretion by 30% and feeding costs by US$7.60/pig (−10%) relative to group feeding. Precision feeding is an effective approach to make pig production more sustainable without compromising growth performance.

Effect of a lysine depletion-repletion protocol on the compensatory growth of growing-finishing pigs.

The effect of Lys restriction followed by a repletion period on the performance of growing pigs was studied during 3 feeding phases, each lasting 28 d. A total of 47 castrated male pigs (G Performer 8.0 × Fertilis 25 pigs; Genetiporc Inc., Saint-Bernard, QC, Canada; initial BW of 26.7 ± 2.7 kg) were given each d 70% or 100% of their Lys requirements according to 1 of the following 5 sequences: 70-70-70, 70-70-100, 70-100-70, 70-100-100, or 100-100-100 (for each sequence, numbers indicate the Lys supply percentage in phase 1, 2, and 3, respectively). Individual Lys requirements were estimated daily on the basis of each pig's actual BW and feed intake and BW gain patterns obtained by regression using each pig's historical data. At the end of phase 1, the pigs given 100% of their Lys requirements had higher ADFI ( = 0.01), ADG ( < 0.01), and average daily protein deposition ( < 0.01) than did the pigs given 70% of their requirements. Similar results were observed during phases 2 and 3. At the end of phase 2, the pigs in the 70-100 sequence did not display any compensatory response, given that their ADFI, ADG, and average daily protein deposition did not differ from those of the pigs in the 100-100 sequence. Similar results were observed during phase 3. Although no compensatory growth was observed during the growing phases, the fact that the pigs in the 70-100-100 treatment were able to catch up in terms of BW and body protein mass to the pigs in the 100-100-100 sequence could indicate that a small degree of compensation did occur; these research results cannot ascertain that any compensatory growth occurred.

Novel Anthropometry-Based Calculation of the Body Heat Capacity in the Korean Population.

Heat capacity (HC) has an important role in the temperature regulation process, particularly in dealing with the heat load. The actual measurement of the body HC is complicated and is generally estimated by body-composition-specific data. This study compared the previously known HC estimating equations and sought how to define HC using simple anthropometric indices such as weight and body surface area (BSA) in the Korean population. Six hundred participants were randomly selected from a pool of 902 healthy volunteers aged 20 to 70 years for the training set. The remaining 302 participants were used for the test set. Body composition analysis using multi-frequency bioelectrical impedance analysis was used to access body components including body fat, water, protein, and mineral mass. Four different HCs were calculated and compared using a weight-based HC (HC_Eq1), two HCs estimated from fat and fat-free mass (HC_Eq2 and HC_Eq3), and an HC calculated from fat, protein, water, and mineral mass (HC_Eq4). HC_Eq1 generally produced a larger HC than the other HC equations and had a poorer correlation with the other HC equations. HC equations using body composition data were well-correlated to each other. If HC estimated with HC_Eq4 was regarded as a standard, interestingly, the BSA and weight independently contributed to the variation of HC. The model composed of weight, BSA, and gender was able to predict more than a 99% variation of HC_Eq4. Validation analysis on the test set showed a very high satisfactory level of the predictive model. In conclusion, our results suggest that gender, BSA, and weight are the independent factors for calculating HC. For the first time, a predictive equation based on anthropometry data was developed and this equation could be useful for estimating HC in the general Korean population without body-composition measurement.

Hypothyroidism, its association with body composition, anthropometric measurements and physical activity levels

Objective: To establish relationship between, body composition, anthropometric measurements and physical activity levels with hypothyroidism. Material and methods: The study was carried out in Pantnagar area of Udham Singh Nagar district, Uttarakhand on 150 female subjects of age between 21 to 50 years, selected by random sampling. The plan of study was carried out in two phases. Basic anthropometric measurements such as weight, height, waist and hip circumference measurements were taken using standard methods. Body composition of the subjects was determined using bioelectrical impedance and physical activity levels of the subjects was also determined in the first phase. Blood samples of the subjects suspected to have hypothyroidism (n = 30) on the basis of symptoms, anthropometric measurements and body composition analysis were also collected for estimation of thyroid hormone levels in the second phase. Results: A significant positive correlation was seen (p ≤ 0.01) in case of anthropometric and body composition parameters such as weight, waist circumference, hip circumference, body mass index and fat mass per cent whereas, in case of fat free mass, total body water, protein, mineral and muscle mass per cent a significant negative correlation was seen with hypothyroidism. On the basis of physical activity pattern there was a significant difference between the average number of hours spent by hypothyroid patients (7.6 ± 0.39) and normal subjects (7.40 ± 0.59) in sleeping, physical work like brisk walking, exercise, jogging or yoga and average number of hours spent in leisure (chatting, socialization, watching T.V., reading magazine, listening to music, napping). There was a non-significant positive correlation between disease and hours spent in sleeping, leisure and household work. Whereas, a non-significant negative correlation was seen between disease and hours spent in personal care/ grooming or hygiene, miscellaneous activities, physical work and occupational work. Conclusion: Conclusively it can be said that individuals with high weight, BMI and waist and hip circumference along with the symptoms like weight gain, puffy face, hands and feet, increased need for sleep, constipation, poor muscle tone (muscle hypotonia), impaired cognitive function (brain fog) and inattentiveness, depression etc. should undergo body composition analysis and biochemical screening for thyroid function so that their status is clear. If in such individuals after body composition analysis fat mass per cent is increased along with decreased fat free mass, total body water, protein, mineral and muscle mass per cent and thyroid function tests are not normal mainly with increased TSH levels and with or without reduced T 3 and T 4 levels then the individuals are suffering from hypothyroidism.

Modelling phosphorus intake, digestion, retention and excretion in growing and finishing pigs: model description

Low phosphorus (P) digestibility combined with intensive pig production can increase P diffuse pollution and environmental load. The aim of this paper was to develop a deterministic, dynamic model able to represent P digestion, retention and ultimately excretion in growing and finishing pigs of different genotypes, offered access to diets of different composition. The model represented the limited ability of pig endogenous phytase activity to dephosphorylate phytate as a linear function of dietary calcium (Ca). Phytate dephosphorylation in the stomach by exogenous microbial phytase enzymes was expressed by a first order kinetics relationship. The absorption of non-phytate P from the lumen of the small intestine into the blood stream was set at 0.8 and the dephosphorylated phytate from the large intestine was assumed to be indigestible. The net efficiency of using digested P was set at 0.94 and assumed to be independent of BW, and constant across genotype and sex. P requirements for both maintenance and growth were made simple functions of body protein mass, and hence functions of animal genotype. Undigested P was assumed to be excreted in the feaces in both soluble and insoluble forms. If digestible P exceeded the requirements for P then the excess digestible P was excreted through the urinary flow; thus the model represented both forms of P excretion (soluble and insoluble) into the environment. Using a UK industry standard diet, model behaviour was investigated for its predictions of P digestibility, retention and excretion under different levels of inclusion of microbial phytase and dietary Ca, and different non-phytate P : phytate ratios in the diet, thus covering a broad space of potential diet compositions. Model predictions were consistent with our understanding of P digestion, metabolism and excretion. Uncertainties associated with the underlying assumptions of the model were identified. Their consequences on model predictions, as well as the model evaluation are assessed in a companion paper.

The impact of daily multiphase feeding on animal performance, body composition, nitrogen and phosphorus excretions, and feed costs in growing–finishing pigs

The effect of feeding pigs in a three-phase feeding (3PF) system or a daily-phase feeding (DPF) system on growth performance, body composition, and N and P excretions was studied on 8 pens of 10 pigs each. Feeds for the 3PF and DPF treatments were obtained by mixing two feeds, one with a high nutrient concentration and the other with a low nutrient concentration. The DPF pigs tended (P=0.08) to consume more feed (+3.7%) than the 3PF pigs, but only during the first feeding phase. The DPF pigs consumed 7.3% less protein (P<0.01) but a similar amount of total P. For the whole growing period, the DPF pigs tended (P=0.08) to gain more weight (+2.4%) than the 3PF pigs, mainly because of faster growth (P=0.02) during the first feeding period. At the end of the experiment, total body protein mass was similar in the two treatment groups, but the DPF pigs had 8% more body lipids (P=0.04) than the 3PF pigs. Daily multiphase feeding reduced N excretion by 12% (P<0.01) but did not significantly reduce P excretion. In addition, feed costs, nutrient intake and nutrient excretion under the two feeding strategies were simulated and compared after different approaches were used to formulate complete feeds for each phase of the 3PF system, as well as the two feeds used in the DPF program. Simulated feed intake and growth was similar to those observed in the animal experiment. In comparison with the simulated 3PF system, the feed cost for the DPF pigs was reduced by 1.0%, the simulated N and P intakes were reduced by 7.3% and 4.4%, respectively, and the expected N and P excretions were reduced by 12.6% and 6.6%, respectively. The concomitant adjustment of the dietary concentration of nutrients to match the evaluated requirements of pig populations can be an efficient approach to significantly reduce feeding costs and N and P excretions in pig production systems.

Leucine improves protein nutritional status and regulates hepatic lipid metabolism in calorie‐restricted rats

Several studies have highlighted the potential of leucine supplementation for the treatment of metabolic diseases including type 2 diabetes and obesity. Caloric restriction is a common approach to improve the health in diabetic and obese subjects. However, very few studies assessed the effects of leucine supplementation in calorie-restricted animals. Rats were subjected to a 30% calorie-restricted diet for 6 weeks to study the effects of leucine supplementation on protein status markers and lipid metabolism. Caloric restriction reduced the body weight. However, increased leucine intake preserved body lean mass and protein mass and improved protein anabolism as indicated by the increased circulating levels of albumin and insulin-like growth factor-1 (IGF-1), and the liver expression of albumin and IGF-1 messenger RNA. Leucine supplementation also increased the circulating levels of interleukin-6 and leptin but did not affect the tumour necrosis factor-α and monocyte chemotactic protein-1 concentrations. Ketone bodies were increased in rats consuming a leucine-rich diet, but we observed no changes in cholesterol or triglycerides concentrations. Caloric restriction reduced the liver expression of peroxisome proliferator activated receptor-α and glucose-6-phosphatase, whereas leucine supplementation increased the liver expression of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-CoA) reductase and sterol regulatory element-binding transcription factor 1. A leucine-rich diet during caloric restriction preserved whole body protein mass and improved markers of protein anabolism. In addition, leucine modulated the hepatic lipid metabolism. These results indicate that increased leucine intake may be useful in preventing excessive protein waste in conditions of large weight loss.

Assessment of nutritional status in children with chronic kidney disease and on dialysis

Protein-energy wasting (PEW) is defined as a state of decreased body protein mass and fuel reserves (body protein and fat mass) and is a common complication of chronic kidney disease (CKD). It is multifactorial: the main causative factors are hormonal imbalances and a low nutrient intake, but low residual renal function, inadequate dialysis dose, chronic inflammation and metabolic acidosis are other important contributory factors. Adult PEW has been defined, but there is no accepted definition of pediatric PEW and consequently no precise diagnostic criteria. Assessing nutritional status in children is also complicated by the absence of a gold standard, specific abnormalities in body composition, and the slowly progressive course of the disease. The evaluation of PEW should take into account all of its pathogenetic aspects, which include dietary assessment, clinical and anthropometric assessment (based on weight, height, and body mass index), a panel of biochemical parameters, and a normalized protein catabolic rate (in the case of adolescents on hemodialysis). Bioimpedance indices can be used in individual patients on a regular basis in centers with expertise. The longitudinal follow-up data relating to the above parameters are valuable for comparing patient and normative data. Given the complex nature of PEW, only a multidisciplinary approach can provide an accurate assessment of nutritional status and its derangements in children with CKD and on dialysis.

Nutritional Assessment and Perioperative Nutritional Support in Gastric Cancer Patients

Weight loss and malnutrition are common in cancer patients. Although weight loss is predominantly due to loss of fat mass, the morbidity risk is given by the decrease in muscle mass. The assessment of nutritional status is essential for a diagnosis of nutritional compromise and required for the multidisciplinary approach. Subjective global assessment (SGA) is made by the patients nutritional symptoms and weight loss. The objective assessment, a significant weight loss (>10%) for 6 months is considered an indicator of nutritional deficiency. The mean body index, body fat mass and body protein mass are decreased as cancer stage increases. The biochemical data of albumin, cholesterol, triglyceride, Zn, transferrin, total lymphocyte count are decreased in advanced cancer stage. Daily energy intake, cabohyderate and Vit B1 intake is decreased according to cancer stage. The patients are divided into three groups according to SGA. The three groups showed a significant difference in body weight, 1 month weight loss%, 6 month weight loss%, body mass index, mid arm circumference, albumin, energy intake, as well as carbohyderate intake protein and energy malnutrition. Nutritional assessment is of great importance because undernutrition has been shown to be associated with increase in stomach cancer associated morbidity and mortality. The authors concluded that nutritional assessment should be done in cancer patients preoperatively, and with adequate nutritional support, the morbidity and mortality would be decreased.