Review of evolution and current status of protein requirements and provision in acute illness and critical care.

Nutrition therapy, by enteral, parenteral, or both routes combined, is a key component of the management of critically ill, surgical, burns, and oncology patients. Established evidence indicates overfeeding (provision of excessive calories) results in increased risk of infection, morbidity, and mortality. This has led to the practice of "permissive underfeeding" of calories; however, this can often lead to inadequate provision of guideline-recommended protein intakes. Acutely ill patients requiring nutritional therapy have high protein requirements, and studies demonstrate that provision of adequate protein can result in reduced mortality and improvement in quality of life. However, a significant challenge to adequate protein delivery is the current lack of concentrated protein solutions. Patients often have fluid administration restrictions and existing protein solutions are frequently not sufficiently concentrated to deliver a patient's protein requirements. This has led to the development of new enteral and parenteral nutrition solutions incorporating higher levels of protein in smaller volumes. This review article summarizes current evidence supporting the role of higher protein intakes, especially during the early phases of nutrition therapy in acute illness, methods for assessing protein requirements, as well as, the currently available high-protein enteral and parenteral nutrition solutions. There is sufficient evidence (albeit limited from true randomized, controlled studies) to indicate that earlier provision of guideline-recommended protein intakes may be key to improving patient outcomes and that nutritional therapy that tailors caloric and protein intake to the patients' needs should be considered a desired standard of care.

History and Design of the INCAP Longitudinal Study (1969-1977) and Its Impact in Early Childhood.

The Institute of Nutrition of Central America and Panama (INCAP) longitudinal study of 1969 to 1977 was a community randomized trial in which 2 pairs of matched villages received either a protein-rich gruel (atole) or a nonprotein, low-energy drink (fresco). Both contained equal amounts of micronutrients by volume. I review the history and design of the study and impact on dietary intakes and physical growth. The design dates from the 1960s when protein was seen as the main dietary deficiency. During the 1970s, emphasis shifted to energy deficiency and this influenced early analyses. Energy from the 2 drinks during pregnancy was associated with improved birthweights and whether protein was also provided along with energy appeared to make no difference. These analyses, observational in nature, were possible because there was substantial overlap in energy intakes from the supplements during pregnancy across village types. In children, analyses initially focused on energy but eventually relied on the original experimental design. Exposure to the atole compared to fresco was associated with improved physical growth at 3 years of age but not from 3 to 7 years. Consumption of the fresco in the first 3 years of life was low such that there was little overlap in energy intakes from the supplements, not allowing for the type of analyses done for pregnancy. Diets in atole villages were greater from 15 to 36 months in protein, energy, and micronutrients, making attribution of impact on growth to a specific nutrient impossible. The atole improved linear growth, arm, and calf circumferences at 3 years but not skinfold thicknesses.

Effect of low-protein intake on all-cause mortality in subjects with an estimated glomerular filtration rate higher than 60 mL/min/1.73 m2 with or without albuminuria.

BACKGROUND: We aimed to investigate the effect of a low-protein intake on all-cause mortality in subjects with an estimated glomerular filtration rate (eGFR) ≧60 mL/min/1.73 m2 with or without albuminuria using data from the National Health and Nutrition Examination Survey (NHANES). METHODS: We analysed participants in the NHANES from 2003 to 2010. We excluded participants with an eGFR less than 60 mL/min/1.73 m2 from the analyses. Low-protein intake was defined as a protein intake of less than 0.8 g/kg/day. The Healthy Eating Index 2010 was used to assess diet quality. The vital status of all participants in the NHANES was determined by linking to the National Death Index through the end of 2011. The hazard ratios (HRs) for the association of low-protein intake and mortality were determined using weighted Cox proportional hazards regression models. RESULTS: A total of 7730 participants were included in the analyses. After a median follow up of 4.7 years, 462 participants died. A low-protein intake was associated with a higher risk of mortality (HRs 1.394, 95% CI 1.121-1.734, P = .004) with adjustment for diet quality and relevant risk factors. The higher risk of mortality associated with a low-protein intake was consistent in subjects with or without albuminuria (P interaction .280). CONCLUSION: A protein intake of less than 0.8 g/kg/day was associated with a higher risk of mortality in subjects with an eGFR ≧60 mL/min/1.73 m2 , irrespective of whether they had albuminuria.

[The Influence of Protein on the Prevention of Fragility Fractures Among Senior Adults]. / Der Einfluss von Protein auf die Prävention von Fragilitätsfrakturen bei älteren Erwachsenen.

The Influence of Protein on the Prevention of Fragility Fractures Among Senior Adults Abstract. The aim of this review article is to discuss protein intake in senior adults at risk for fragility fractures as a modifiable factor for fracture prevention. Proteins are building blocks of the bone matrix and the muscles. This dual function fits in with the concept of prevention of fragility fractures in senior adults aimed at reducing both bone loss and falls. In older adults, a protein-rich diet could be another simple and effective way to promote bone and muscle health, in addition to the established recommendations for adequate vitamin D and calcium intake.

The relevance of dietary protein after bariatric surgery: what do we know?

PURPOSE OF REVIEW: The growing obesity epidemic is associated with an increased demand for bariatric surgery with Roux-en-Y Gastric Bypass and Sleeve Gastrectomy as the most widely performed procedures. Despite beneficial consequences, nutritional complications may arise because of anatomical and physiological changes of the gastrointestinal tract. The purpose of this review is to provide an update of the recent additions to our understanding of the impact of bariatric surgery on the intake, digestion and absorption of dietary protein. RECENT FINDINGS: After bariatric surgery, protein intake is compromised because of reduced gastric capacity and aversion for certain foods. A minority of patients reaches the recommended protein intake of minimal 60 g per day, which results in the loss of fat-free mass rather than the desired loss of fat mass. Despite inadequate protein intake, protein digestion and absorption do not seem to be impaired suggesting that other mechanisms could counteract the reduced secretion of digestive enzymes and their delayed inlet. SUMMARY: After bariatric surgery, protein supplementation or diet enrichment could attribute to achieve the minimal recommended protein intake and benefit the amount and composition of postoperative weight loss.

Potential application of microalga Spirulina platensis as a protein source.

The high protein level of various microalgal species is one of the main reasons to consider them an unconventional source of this compound. Spirulina platensis stands out for being one of the richest protein sources of microbial origin (460-630 g kg-1 , dry matter basis), having similar protein levels when compared to meat and soybeans. The use of S. platensis in food can bring benefits to human health owing to its chemical composition, since it has high levels of vitamins, minerals, phenolics, essential fatty acids, amino acids and pigments. Furthermore, the development of new protein sources to supply the shortage of this nutrient is an urgent need, and protein from S. platensis plays an important role in this scenario. In this sense, extraction processes that allow maximum protein yield and total utilization of biomass is an urgent need, and ultrasonic waves have proven to be an effective extraction technique. The number of scientific papers related to protein fraction from S. platensis is still limited; thus further studies on its functional and technological properties are needed. © 2016 Society of Chemical Industry.

Protein and Older Persons.

An optimal protein intake is important for the preservation of muscle mass, functionality, and quality of life in older persons. In recent years, new recommendations regarding the optimal intake of protein in this population have been published. Based on the available scientific literature, 1.0 to 1.2 g protein/kg body weight (BW)/d are recommended in healthy older adults. In certain disease states, a daily protein intake of more than 1.2 g/kg BW may be required. The distribution of protein intake over the day, the amount per meal, and the amino acid profile of proteins are also discussed.

[DIETARY PREVENTION OF PROTEIN-ENERGY MALNUTRITION IN ELDERLY PATIENTS IN THE POSTOPERATIVE PERIOD].

The occurrence of protein-energy malnutrition in the late postoperative period in elderly patients with gastroduodenal ulcers is an indication for the earliest possible appointment of a specialized diet the prevention of this complication. Specific dietary recommendations for the prevention of protein-energy malnutrition in the postoperative period were given.

Validación de los menús escolares de acuerdo a los estándares recomendados / Validation of menus in accordance with the recommended standards

Fundamentos: Los cambios realizados en los últimos años en los países occidentalizados han contribuido al incremento de los usuarios en los comedores colectivos, en empresas y colegios. En este trabajo se valoran los menús escolares atendiendo a las normas descritas a nivel nacional y autonómico para la prevención de enfermedades y mejora del estado de salud. Métodos: Se analizan tres menús consecutivos de una empresa de restauración colectiva de 20 días cada uno, divididos en bloques de 5 días simulando la semana de ingesta en el comedor escolar, para usuarios entre 9 y 13 años. Resultados: Los menús analizados suministran un aporte energético medio de 32,6% de la energía diaria, dentro del rango recomendado. Sin embargo, destaca un elevado aporte proteico (20,1%) centrado en el consumo de lácteos, carnes magras, pescados blancos y huevos. Los aportes suministrados de vitamina C, vitamina A y hierro permiten satisfacer los requerimientos medios estimados. Sin embargo, para el calcio y vitamina E no debiéndose complementar con los aportes domésticos. Conclusiones: Los menús escolares analizados ofrecen un aporte energético de acuerdo a las recomendaciones, aunque destaca una contribución elevada a partir de la ingesta proteica. La intervención de dietistas-nutricionistas en el diseño y planificación de los menús suministrados permite una mejor configuración nutricional, la evaluación continuada y mejora de la oferta, además de su potencial contribución al asesoramiento individual y otras actividades de información-educación nutricional (AU)

Background: The changes that are taking place in recent years in western countries have shown an increase in the number of users in the canteens, both in companies and in schools. In this paper school menus are assessed according to the standards established at national and regional level for disease prevention and health improvement. Methods: We analyzed three consecutive menus offered by a catering company of 20 days each, divided into blocks of five days a week simulating intake in the cafeteria for users between 9 and 13 years. Results: The analyzed menus provide an average energy intake of 32.6 % of the daily energy, within the recommended range. Result highlight a large contribution from the protein intake (20.1%) provided by the consumption of dairy, lean meats, fish and eggs. The amounts provided of vitamin C, vitamin A and iron satisfy the estimated average requirements for these nutrients However, those for calcium and vitamin E do not meet the daily requirement and must be complemented with domestic contributions. Conclusions: The school menus analyzed provide an energy intake according to recommendations, but a high contribution from protein intake . The involvement of nutritionists - dietitians in the design and planning of school menus contributes to a better nutrition profile of the offer and enables continuous assessment and improvement of the offer, in addition to its potential contribution to individual counseling and other nutritional information-education activities (AU)

Treatment of metabolic syndrome by combination of physical activity and diet needs an optimal protein intake: a randomized controlled trial.

BACKGROUND: The recommended dietary allowance (RDA) for protein intake has been set at 1.0-1.3 g/kg/day for senior. To date, no consensus exists on the lower threshold intake (LTI = RDA/1.3) for the protein intake (PI) needed in senior patients ongoing both combined caloric restriction and physical activity treatment for metabolic syndrome. Considering that age, caloric restriction and exercise are three increasing factors of protein need, this study was dedicated to determine the minimal PI in this situation, through the determination of albuminemia that is the blood marker of protein homeostasis. METHODS: Twenty eight subjects (19 M, 9 F, 61.8 ± 6.5 years, BMI 33.4 ± 4.1 kg/m²) with metabolic syndrome completed a three-week residential programme (Day 0 to Day 21) controlled for nutrition (energy balance of -500 kcal/day) and physical activity (3.5 hours/day). Patients were randomly assigned in two groups: Normal-PI (NPI: 1.0 g/kg/day) and High-PI (HPI: 1.2 g/kg/day). Then, patients returned home and were followed for six months. Albuminemia was measured at D0, D21, D90 and D180. RESULTS: At baseline, PI was spontaneously 1.0 g/kg/day for both groups. Albuminemia was 40.6 g/l for NPI and 40.8 g/l for HPI. A marginal protein under-nutrition appeared in NPI with a decreased albuminemia at D90 below 35 g/l (34.3 versus 41.5 g/l for HPI, p < 0.05), whereas albuminemia remained stable in HPI. CONCLUSION: During the treatment based on restricted diet and exercise in senior people with metabolic syndrome, the lower threshold intake for protein must be set at 1.2 g/kg/day to maintain blood protein homeostasis.

High-carbohydrate/low-protein-induced hyperinsulinemia does not improve protein balance in children after cardiac surgery.

OBJECTIVE: In pediatric cardiac surgery, fluid-restricted low-protein (LoProt) diets account for cumulative protein deficits with increased morbidity. In this setting, we aimed to inhibit proteolysis by a high-carbohydrate (HiCarb)-intake-induced hyperinsulinemia and improve protein balance. METHODS: The effect of a HiCarb/LoProt (glucose 10 mg · kg(-1) · min(-1)/protein 0.7 g · kg(-1) · d(-1)) versus a normal-carbohydrate (NormCarb)/LoProt (glucose 7.5 mg · kg(-1) · min(-1)/protein 0.3 g · kg(-1) · d(-1)) enteral diet on whole-body protein breakdown and balance was compared in a prospective, randomized, single-blinded trial in 24 children after cardiac surgery. On the second postoperative day, plasma insulin and amino acid concentrations, protein breakdown (endogenous rate of appearance of valine), protein synthesis (non-oxidative disposal of valine), protein balance, and the rate of appearance of urea were measured by using an isotopic infusion of [1-(13)C]valine and [(15)N(2)]urea. RESULTS: The HiCarb/LoProt diet led to a serum insulin concentration that was three times higher than the NormCarb/LoProt diet (596 pmol/L, 80-1833, and 198 pmol/L, 76-1292, respectively, P = 0.02), without differences in plasma glucose concentrations. There were no differences in plasma amino acid concentrations, non-oxidative disposal of valine, and endogenous rate of appearance of valine between the groups, with a negative valine balance in the two groups (-0.65 µmol · kg(-1) · min(-1), -1.91 to 0.01, and -0.58 µmol · kg(-1) · min(-1), -2.32 to -0.07, respectively, P = 0.71). The serum cortisol concentration in the HiCarb/LoProt group was lower compared with the NormCarb/LoProt group (204 nmol/L, 50-544, and 532 nmol/L, 108-930, respectively, P = 0.02). CONCLUSION: In children with fluid restriction after cardiac surgery, a HiCarb/LoProt diet compared with a NormCarb/LoProt diet stimulates insulin secretion but does not inhibit proteolysis further and therefore cannot be advocated for this purpose.

Protein requirements in the elderly.

Adequate protein intake and the maintenance of nitrogen equilibrium are of particular importance in the elderly because this age group is at increased risk of illness and malnutrition. The current recommendation for protein intake of healthy elderly subjects is 0.8 g/kg body weight/day, the same as for younger adults. Nitrogen balance studies in the elderly, however, revealed conflicting results; some studies suggest that not all elderly can achieve a nitrogen balance with a protein intake of 0.8 g/kg body weight/day, particularly if energy supply is not adequate. Beyond the amount of protein needed for nitrogen balance, the optimal protein intake for preservation of lean body mass, body functions, and health is of paramount interest. At present, there is insufficient longer-term research with defined health outcomes to derive recommendations in this regard. Very little is also known about the protein needs of frail and unhealthy elderly. Until more evidence is available, it seems reasonable to ensure a protein intake of at least 0.8 g/kg body weight/day in all elderly persons, particularly in those at risk of malnutrition (e.g., frail and multimorbid elderly). In addition to ascertaining adequate protein and energy intake, physical activity should be encouraged in order to increase energy expenditure and food intake and to facilitate muscle protein anabolism.

Protein intake in renal and hepatic disease.

The kidney and the liver play a central role in protein metabolism. Synthesis of albumin and other proteins occurs mainly in the liver, whereas protein breakdown and excretion are handled through an intricate interaction between these two organ systems. Thus, disease states of either the liver and/or the kidney invariably result in clinically relevant disturbances of protein metabolism. Conversely, metabolic processes regulated by these two organs are directly affected by dietary protein intake. Of particular importance in this respect is the maintenance of acid/base homeostasis. Finally, both the amount and composition of ingested proteins have a direct impact on renal function, especially in a state of diseased kidneys. Consequently, dietary protein intake is of paramount importance in patients with chronic nephropathy and renal insufficiency. Limitation of ingested protein, particularly from animal sources, is crucial in order to slow the progression of chronic kidney disease and impaired renal function. In contrast, patients with chronic renal failure undergoing renal replacement therapy by hemodialysis or peritoneal dialysis, have an increased protein demand. The syndrome of "protein-energy malnutrition" is a relevant factor for morbidity and mortality in this population and requires early detection and vigorous treatment. Protein intake in patients with cirrhosis of the liver should not be diminished as has been earlier suggested but rather increased to 1.0 - 1.2 g/kg body weight/day, in order to prevent protein malnutrition. Moderate restriction depending on protein tolerance (0.5 - 1.2 g/kg body weight/day), with the possible addition of branched chain amino acids (BCAA), has been recommended only in patients with advanced hepatic encephalopathy. Proteins of plant origin are theoretically superior to animal proteins.

Protein dietary reference intakes may be inadequate for vegetarians if low amounts of animal protein are consumed.

OBJECTIVE: The health benefits of vegetarian diets are well-recognized; however, long-term adherence to these diets may be associated with nutrient inadequacies, particularly vitamins B12 and D, calcium, iron, zinc, and protein. The dietary reference intakes (DRIs) expert panels recommended adjustments to the iron, zinc, and calcium DRIs for vegetarians to account for decreased bioavailability, but no adjustments were considered necessary for the protein DRI under the assumption that vegetarians consume about 50% of protein from animal (dairy/egg) sources. This study examined dietary protein sources in a convenience sample of 21 young adult vegetarian women who completed food logs on 4 consecutive days (3 weekdays and 1 weekend day). METHODS: The daily contribution percentages of protein consumed from cereals, legumes, nuts/seeds, fruits/vegetables, and dairy/egg were computed, and the protein digestibility corrected amino acid score of the daily diets was calculated. RESULTS: The calculated total dietary protein digestibility score for participants was 82 ± 1%, which differed significantly (P < 0.001) from the DRI reference score, 88%, and the 4-d average protein digestibility corrected amino acid score for the sample was 80 ± 2%, which also differed significantly (P < 0.001) from the DRI reference value, 100%. The analyses indicated that animal protein accounted for only 21% of dietary protein. CONCLUSION: This research suggests that the protein DRI for vegetarians consuming less than the expected amounts of animal protein (45% to 50% of total protein) may need to be adjusted from 0.8 to about 1.0 g/kg to account for decreased protein bioavailability.

Fluid, electrolytes, and nutrition: minutes matter.

Historically, in very low-birth-weight infant care, nutritional support was delayed during the first postnatal days because of fear of toxicity and harm with immature metabolic systems and intestinal function. Recent evidence demonstrates that early nutritional support is not only safe but likely necessary to optimize infant growth and neurodevelopment. In fact, nutrition management is a critical factor in very low-birth-weight infant golden hour support. Contemporary studies in protein and lipid intravenous support and early feeds as minimal enteral nutrition exhibit safety and some efficacy. We will present analysis of this evidence and development of potential better practices on the basis of these data as well as a review of golden hour fluid and glucose management. In addition, we provide several outcomes following our adoption of potentially better golden hour nutrition practices.

The importance of dietary protein in human health: combating protein deficiency in sub-Saharan Africa through transgenic biofortified sorghum.

Child malnutrition is increasing in Africa. Protein deficiency is an important cause since protein is essential for both growth and maintenance of muscle mass. Sorghum is a major staple food in Africa on account of its hardiness as a crop. However, sorghum protein is very deficient in the indispensable amino acid lysine and on cooking has poor protein digestibility. This results in sorghum having a very low Protein Digestibility Corrected Amino Acid Score (PDCAAS). The Africa Biofortified Sorghum project, a Grand Challenges in Global Heath project, is undertaking research to biofortify sorghum in terms of protein and micronutrient quality using genetic engineering. Lysine and protein digestibility have been improved by suppression of synthesis of the kafirin storage proteins. Transgenic biofortified sorghum has double the PDCAAS of conventional sorghum. This improvement should enable a young child to meet most of its protein and energy requirements from biofortified sorghum porridge. This together with the improvement in micronutrients could provide the basis of a sustainable and broadly comprehensive solution to child malnutrition in many African countries.