Levels Of Protein Intake Research Articles

Quantity of dietary protein intake, but not pattern of intake, affects net protein balance primarily through differences in protein synthesis in older adults.

To examine whole body protein turnover and muscle protein fractional synthesis rate (MPS) following ingestions of protein in mixed meals at two doses of protein and two intake patterns, 20 healthy older adult subjects (52-75 yr) participated in one of four groups in a randomized clinical trial: a level of protein intake of 0.8 g (1RDA) or 1.5 g·kg(-1)·day(-1) (∼2RDA) with uneven (U: 15/20/65%) or even distribution (E: 33/33/33%) patterns of intake for breakfast, lunch, and dinner over the day (1RDA-U, 1RDA-E, 2RDA-U, or 2RDA-E). Subjects were studied with primed continuous infusions of L-[(2)H5]phenylalanine and L-[(2)H2]tyrosine on day 4 following 3 days of diet habituation. Whole body protein kinetics [protein synthesis (PS), breakdown, and net balance (NB)] were expressed as changes from the fasted to the fed states. Positive NB was achieved at both protein levels, but NB was greater in 2RDA vs. 1RDA (94.8 ± 6.0 vs. 58.9 ± 4.9 g protein/750 min; P = 0.0001), without effects of distribution on NB. The greater NB was due to the higher PS with 2RDA vs. 1RDA (15.4 ± 4.8 vs. -18.0 ± 8.4 g protein/750 min; P = 0.0018). Consistent with PS, MPS was greater with 2RDA vs. 1RDA, regardless of distribution patterns. In conclusion, whole body net protein balance was greater with protein intake above recommended dietary allowance (0.8 g protein·kg(-1)·day(-1)) in the context of mixed meals, without demonstrated effects of protein intake pattern, primarily through higher rates of protein synthesis at whole body and muscle levels.

Protein intake and lumbar bone density: the Multi-Ethnic Study of Atherosclerosis (MESA).

Dietary protein has been shown to increase urinary Ca excretion in randomised controlled trials, and diets high in protein may have detrimental effects on bone health; however, studies examining the relationship between dietary protein and bone health have conflicting results. In the present study, we examined the relationship between dietary protein (total, animal and vegetable protein) and lumbar spine trabecular volumetric bone mineral density (vBMD) among participants enrolled in the Multi-Ethnic Study of Atherosclerosis (n 1658). Protein intake was assessed using a FFQ obtained at baseline examination (2000-2). Lumbar spine vBMD was measured using quantitative computed tomography (2002-5), on average 3 years later. Multivariable linear and robust regression techniques were used to examine the associations between dietary protein and vBMD. Sex and race/ethnicity jointly modified the association of dietary protein with vBMD (P for interaction=0·03). Among white women, higher vegetable protein intake was associated with higher vBMD (P for trend=0·03), after adjustment for age, BMI, physical activity, alcohol consumption, current smoking, educational level, hormone therapy use, menopause and additional dietary factors. There were no consistently significant associations for total and animal protein intakes among white women or other sex and racial/ethnic groups. In conclusion, data from the present large, multi-ethnic, population-based study suggest that a higher level of protein intake, when substituted for fat, is not associated with poor bone health. Differences in the relationship between protein source and race/ethnicity of study populations may in part explain the inconsistent findings reported previously.

STUDI KETAHANAN PANGAN PADA RUMAHTANGGA MISKIN DAN TIDAK MISKIN

Food security at household level refers to the ability to ensure an adequate intake of food for the whole family members. Food security includes physical (food availability), economical (purchasing power), nutritional (fulfilled individual need of adequate nutrient), cultural and religious aspects, health, and time. The objective of this study was to identify factors affecting food security of the households. The study was conducted in a highland area of Bogor District and a coastal area of Indramayu District, West Java, Indonesia. In Bogor, 375 samples and in Indramayu 376 samples were selected randomly. The data collected through questionnaires were tried out before hand so that they were more operational. The revised questionnaires and forms then were used by the enumerators. Food security reflected by the sufficiency level of energy and protein intake shows that in general poor households have a low level of nutritional. Households in Indramayu have a higher food security than those in Bogor (particularly in terms of protein sufficiency). Factors having a significant association on food security of households were the number of household members, husband ages, and household category. The number of members in households affect significantly the energy sufficiency level. The number of members in households, husbands’ ages, and household category have a significant effect on the level of protein sufficiency. Key words : food security, energy sufficiency, protein sufficiency.

Considerations for protein intake in managing weight loss in athletes

A large body of evidence now shows that higher protein intakes (2–3 times the protein Recommended Dietary Allowance (RDA) of 0.8 g/kg/d) during periods of energy restriction can enhance fat-free mass (FFM) preservation, particularly when combined with exercise. The mechanisms underpinning the FFM-sparing effect of higher protein diets remain to be fully elucidated but may relate to the maintenance of the anabolic sensitivity of skeletal muscle to protein ingestion. From a practical point of view, athletes aiming to reduce fat mass and preserve FFM should be advised to consume protein intakes in the range of ∼1.8–2.7 g kg−1 d−1 (or ∼2.3–3.1 g kg−1 FFM) in combination with a moderate energy deficit (−500 kcal) and the performance of some form of resistance exercise. The target level of protein intake within this recommended range requires consideration of a number of case-specific factors including the athlete's body composition, habitual protein intake and broader nutrition goals. Athletes should focus on consuming high-quality protein sources, aiming to consume protein feedings evenly spaced throughout the day. Post-exercise consumption of 0.25–0.3 g protein meal−1 from protein sources with high leucine content and rapid digestion kinetics (i.e. whey protein) is recommended to optimise exercise-induced muscle protein synthesis. When protein is consumed as part of a mixed macronutrient meal and/or before bed slightly higher protein doses may be optimal.

Gut microbiota. Tackling the effects of diet and exercise on the gut microbiota.

A new study published in Gut highlights that high levels of exercise and an accompanying high-protein diet are associated with changes to the gut microbiota, with elite athletes having a more diverse range of microorganisms in their gut than control individuals. “In addition to microbial diversity, we also found specific compositional changes in the [gut] microbiota of the athletes, including a significant increase in the abundance of Akkermansia muciniphila,” notes author Fergus Shanahan. The vast majority of studies investigating the gut microbiota have focused on the effects of obesity, disease or dietary excess (high-fat diets). As awareness increases about the influence of the gut microbiota on health, attention has turned to how the modern lifestyle (such as poor diet and low levels of exercise) might have a role in maintaining a healthy gut microbiota. Shanahan and colleagues examined the gut microbiota of professional rugby players at a preseason training camp (n = 40) as well as two different control groups of healthy individuals matched for age and gender, but split by BMI (low BMI ≤25, n = 23; high BMI >28, n = 23) to account for the large physical size of the rugby players. Nutritional (including detailed information on diet) and clinical data were collected for all participants, as well as metagenomic compositional analysis of the faecal microbiota. As expected, athletes had higher plasma levels of creatine kinase (a marker of extreme exercise) than controls; lower levels of inflammatory markers and improvements in metabolic markers were also observed. Moreover, compared with controls, athletes had a more diverse range of microbes in their gut—22 distinct phyla versus only 11 and nine phyla in the low-BMI and high-BMI controls, respectively. Importantly, this change in diversity positively correlated with protein intake and creatine kinase levels. “An important caveat to the study is that the athletes’ diet differed from that of the controls,” warns Shanahan. “They eat more of everything than the controls, but particularly protein supplements.” As such, further prospective studies are now planned to separate out the effects of exercise from the dietary changes that often accompany a healthy lifestyle in general. Crucially, more work is needed to prove that exercise has a direct effect on the gut microbiota and a causative role in changing the diversity of these microbes.

Essential nutrient requirements of the elderly

Essential nutrient requirements of the elderly Robert Skully Department of Family Medicine, Grant Medical Center, OhioHealth, Columbus, OH, USA Abstract: Government-sponsored medical organizations in developed countries have established guidelines for daily nutritional requirements. For most nutrients there is general agreement surrounding these requirements, which are based on exhaustive scientific literature review. Differences in these recommendations exist because of genetic and environmental factors that result in differences in disease susceptibility, but also due to incomplete understanding of the roles of nutrients in disease prevention. This review briefly summarizes nutrient recommendations for older adults such as where those recommendations differ from those of younger adults; and includes areas of developing understanding such as the possible role of thiamine deficiency in patients with congestive heart failure, the need for some older adults to ingest absorbable forms of vitamin B12, the high prevalence of vitamin D deficiency, the potential role of vitamin K in bone health, the need for higher levels of protein intake in order to stimulate muscle protein synthesis as one ages, the role of calcium in osteoporosis, and the possible need for zinc supplementation in hospitalized patients. Keywords: vitamins, nutritional requirements, energy expenditure, energy consumption

Status Anemi Ibu Hamil Trimester III Sebagai Efek Tingkat Kepatuhan Konsumsi Tablet Fe, Protein, Vitamin C dan Pengetahuannya

BackgroundAnemia in pregnant women is still a big problem in Indonesia, and it can increase the mortality and morbidity of the mothers and babies. According to the Basic Health Research report 2007 showed that the prevalence of anemia in Central Java province reached 16.4 % and it is above the national prevalence of anemia 14.8 %. At the Mijen I health center 42,86% of 70 pregnant women were examined have haemoglobin less than 11g%Objective : To analyze the relationship between Fe tablet intake , protein ,vitamin C , and the knowledge, with the anemia status of third Trimester pregnant women..Method:The study was an observational analytic by using cross sectional approach. Held in December 2013 to January 2014. It is the total population of third trimester pregnant women that there are 44 pregnant women. Using The questionnaire which is consist of the identity of respondents, the level of knowledge. Fe tablet intake protein and vitamin C intake, recall 24 hours was done for two days, and photometer for measuring hemoglobin levels.Results : Fe tablet intake of respondents on average 56.8 % obedient, good protein intake as much as 59.1 % of respondents , majority of the respondents have less knowledge of the number 25 (56.8 %) of the respondents and the total of 61.4 % of respondents are not anemicConclusion: There is a significant relationship between adherences to consume Fe with maternal anemia status. There is a significant relationship between the level of protein intake with anemia status. There is a significant relationship between the consumption of Vitamin C it anemia status. There is a significant relationship between the levels of knowledge of the status of anemia

Higher versus lower protein intake in formula-fed low birth weight infants.

The ideal quantity of dietary protein for formula-fed low birth weight infants is still a matter of debate. Protein intake must be sufficient to achieve normal growth without negative effects such as acidosis, uremia, and elevated levels of circulating amino acids. To determine whether higher (≥ 3.0 g/kg/d) versus lower (< 3.0 g/kg/d) protein intake during the initial hospital stay of formula-fed preterm infants or low birth weight infants (< 2.5 kilograms) results in improved growth and neurodevelopmental outcomes without evidence of short- and long-term morbidity.To examine the following distinctions in protein intake. 1. Low protein intake if the amount was less than 3.0 g/kg/d. 2. High protein intake if the amount was equal to or greater than 3.0 g/kg/d but less than 4.0 g/kg/d. 3. Very high protein intake if the amount was equal to or greater than 4.0 g/kg/d.If the reviewed studies combined alterations of protein and energy, subgroup analyses were to be carried out for the planned categories of protein intake according to the following predefined energy intake categories. 1. Low energy intake: less than 105 kcal/kg/d. 2. Medium energy intake: greater than or equal to 105 kcal/kg/d and less than or equal to 135 kcal/kg/d. 3. High energy intake: greater than 135 kcal/kg/d.As the Ziegler-Fomon reference fetus estimates different protein requirements for infants based on birth weight, subgroup analyses were to be undertaken for the following birth weight categories. 1. < 800 grams. 2. 800 to 1199 grams. 3. 1200 to 1799 grams. 4. 1800 to 2499 grams. The standard search methods of the Cochrane Neonatal Review Group were used. MEDLINE, CINAHL, PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library) were searched. Randomized controlled trials contrasting levels of formula protein intake as low (< 3.0 g/kg/d), high (≥ 3.0 g/kg/d but < 4.0 g/kg/d), or very high (≥ 4.0 g/kg/d) in formula-fed hospitalized neonates weighing less than 2.5 kilograms were included. Studies were excluded if infants received partial parenteral nutrition during the study period or were fed formula as a supplement to human milk. Studies in which nutrients other than protein also varied were added in a post-facto analysis. The standard methods of the Cochrane Neonatal Review Group were used. Five studies compared low versus high protein intake. Improved weight gain and higher nitrogen accretion were demonstrated in infants receiving formula with higher protein content while other nutrients were kept constant. No significant differences were seen in rates of necrotizing enterocolitis, sepsis, or diarrhea.One study compared high versus very high protein intake during and after an initial hospital stay. Very high protein intake promoted improved gain in length at term, but differences did not remain significant at 12 weeks corrected age. Three of the 24 infants receiving very high protein intake developed uremia.A post-facto analysis revealed further improvement in all growth parameters in infants receiving formula with higher protein content. No significant difference in the concentration of plasma phenylalanine was noted between high and low protein intake groups. However, one study (Goldman 1969) documented a significantly increased incidence of low intelligence quotient (IQ) scores among infants of birth weight less than 1300 grams who received a very high protein intake (6 to 7.2 g/kg). Higher protein intake (≥ 3.0 g/kg/d but < 4.0 g/kg/d) from formula accelerates weight gain. However, limited information is available regarding the impact of higher formula protein intake on long-term outcomes such as neurodevelopmental abnormalities. Available evidence is not adequate to permit specific recommendations regarding the provision of very high protein intake (> 4.0 g/kg/d) from formula during the initial hospital stay or after discharge.

Quantity of dietary protein, but not pattern of intake, affects net protein accretion in older adults (272.4)

We examined 16‐h whole body protein turnover [protein synthesis (PS), breakdown (PB), and net balance (NB), expressed as delta changes from the fasted state] in four permutations: a level of protein intake of 0.8g/kg/day (1RDA) or 1.5g/kg/day (2RDA) with an uneven [U: 15/20/65%)] or even distribution patterns of intake (E: 33/33/33%) for breakfast, lunch, &amp;amp; dinner of intake over the day. Twenty healthy older subjects were randomly assigned into one of 4 groups: 1RDA‐U, 1RDA‐E, 2RDA‐U, or 2RDA‐E, and were studied with primed continuous infusions of ring‐[2H5]phenylalanine &amp;amp; ring‐[2H2]tyrosine on day 4 following 3 days of diet habituation. Positive NB was achieved at both protein levels, but NB was significantly greater in 2RDA vs. 1RDA [NB: 94.75 ± 6.01 vs. 58.86 ± 4.91 g protein/kg/750min; p = 0.0001], without effects of distribution on NB. The greater NB was due to the higher PS with 2RDA vs. 1RDA [PS: 15.40 ± 4.84 vs. ‐17.98 ± 8.44 g protein/kg/750min; p = 0.0018]. PS was significantly correlated with delta changes of mean plasma concentrations of leucine from the fasted state (R2 = 0.51, p = 0.0004). We conclude that in the context of mixed meals whole body net protein accretion is greater with protein intake above recommended dietary allowance (0.8 g protein/kg/day), regardless of protein intake pattern, primarily through increased protein synthesis.Grant Funding Source: Supported by Dairy Research Institute and Award Number UL1TR000039 and KL2TR000063 (NCATS and NIH)

Animal Protein Intake Is Associated with Higher‐Level Functional Capacity in Elderly Adults: The Ohasama Study

To determine the association between protein intake and risk of higher-level functional decline in older community-dwelling adults. Prospective. Ohasama Town, Japan. Residents (N = 1,007; mean age 67.4 ± 5.5) free of functional decline at baseline; follow-up was conducted for 7 years. Nutrient and food intakes were determined using a validated 141-item food frequency questionnaire. Participants were divided into quartiles according to intake levels of total, animal, and plant protein. Subscales of the Tokyo Metropolitan Institute of Gerontology Index of Competence subscales were used to assess higher-level functional decline. Logistic regression analysis was used to examine the future risk of higher-level functional decline in relation to protein intake, with lowest protein intake as reference. During the study period, 24.4% of eligible participants reported declines in higher-level functional capacity. After adjustment for putative confounding factors, men in the highest quartile of animal protein intake had significantly lower risk of higher-level functional decline than those in the lowest quartile (odds ratio (OR) = 0.41, 95% confidence interval (CI) = 0.20-0.83; P for trend .01). These associations were not seen in women (OR = 0.76, 95% CI = 0.41-1.34; P for trend .37). No consistent association was observed between plant protein intake and future higher-level functional decline in either sex. Higher protein, particularly animal protein, was associated with lower risk of decline in higher-level functional capacity in older men. Animal protein intake may be a modifiable indicator for early detection and prevention of higher-level functional decline in elderly adults.

Quantitative Analysis of Fish Consumption in Rivers State, Nigeria

The determinants of demand for fish in Rivers State were isolated in this study. Structured questionnaire was used in eliciting information from the respondents. Cross sectional data were randomly collected fr om 210 respondents from the three senatorial zones. Multiple regression analysis was used in analyzing the data. Results showed that age, household size, income, price of beef and sex of the consumers were the major determinants of fish consumption in the State. The demand for fish was relatively income inelastic. Beef was a close substitute to fish therefore an increase in the price of beef leads to a corresponding increase in the quantity of fish demanded. Fish was a normal good. Policies and programmes aimed at raising the income of households such as credit liberalization should be implemented by the government. In addition the level of education of the citizens should be raised through compulsory secondary education so as to increase the level of theirnutritional enlightenment which is expected to boost their levels of protein intake.

Dietary supplementation of propionylated starch to domestic cats provides propionic acid as gluconeogenic substrate potentially sparing the amino acid valine.

In strict carnivorous domestic cats, a metabolic competition arises between the need to use amino acids for gluconeogenesis and for protein synthesis both in health and disease. The present study investigated the amino acid-sparing potential of propionic acid in cats using dietary propionylated starch (HAMSP) supplementation. A total of thirty cats were fed a homemade diet, supplemented with either HAMSP, acetylated starch (HAMSA) or celite (Control) for three adaptation weeks. Propionylated starch was hypothesised to provide propionic acid as an alternative gluconeogenic substrate to amino acids, whereas acetic acid from HAMSA would not provide any gluconeogenic benefit. Post-adaptation, a 5-d total faecal collection was carried out to calculate apparent protein digestibility coefficients. Fresh faecal and blood samples were collected to analyse fermentation endproducts and metabolites. The apparent protein digestibility coefficients did not differ between supplements (P=0·372) and were not affected by the protein intake level (P=0·808). Faecal propionic acid concentrations were higher in HAMSP than in HAMSA (P=0·018) and Control (P=0·003) groups, whereas concentrations of ammonia (P=0·007) were higher in HAMSA than in HAMSP cats. Tendencies for or higher propionylcarnitine concentrations were observed in HAMSP compared with HAMSA (P=0·090) and Control (P=0·037) groups, and for tiglyl-+3-methylcrotonylcarnitine concentrations in HAMSP as compared with Control (P=0·028) cats. Methylmalonylcarnitine concentrations did not differ between groups (P=0·740), but were negatively correlated with the protein intake level (r -0·459, P=0·016). These results suggest that HAMSP cats showed more saccharolytic fermentation patterns than those supplemented with HAMSA, as well as signs of sparing of valine in cats with a sufficient protein intake.

Protein Intake and Growth in Preterm Infants: A Systematic Review.

Objective. This review aimed to investigate the relationship between varying levels of enteral protein intake and growth in preterm infants, regardless of feeding method. Data Sources. Electronic databases were searched for relevant studies, as were review articles, reference lists, and text books. Study Selection. Trials were included if they were randomized or quasirandomized, participants were <37 weeks gestation at birth, and protein intakes were intentionally or statistically different between study groups. Trials reporting weight, length, and head circumference gains in infants fed formula, human milk, or fortified human milk were included. Data Extraction. Studies were categorized by feeding-type and relevant data were extracted into summary tables by one reviewer and cross-checked by a second. Data Synthesis. A meta-analysis could not be conducted due to extensive variability among studies; thus, results were synthesized graphically and narratively. Twenty-four trials met the inclusion criteria and were included in a narrative synthesis and 19 in a graphical synthesis of study results. Conclusions. There was extensive variability in study design, participant characteristics, and study quality. Nonetheless, results are fairly consistent that higher protein intake results in increased growth with graphical representation indicating a potentially linear relationship. Additionally, intakes as high as 4.5 g/kg/day were shown to be safe in infants weighing >1000 g.

Hyperphosphatemia is a combined function of high serum PTH and high dietary protein intake in dialysis patients

Elevated serum phosphorus is associated with higher death risk in hemodialysis patients. Previous studies have suggested that both higher serum parathyroid hormone (PTH) level and higher dietary protein intake may contribute to higher serum phosphorus levels. However, it is not well known how these two factors simultaneously contribute to the combined risk of hyperphosphatemia in real patient-care scenarios. We hypothesized that the likelihood of hyperphosphatemia increases across higher serum PTH and higher normalized protein catabolic rate (nPCR) levels, a surrogate of protein intake. Over an 8-year period (July 2001–June 2009), we identified 69,355 maintenance hemodialysis patients with PTH, nPCR, and phosphorus data in a large dialysis provider. Logistic regression models were examined to assess the association between likelihood of hyperphosphatemia (serum phosphorus >5.5 mg/dl) and serum PTH and nPCR increments. Patients were 61±15 years old and included 46% women, 33% blacks, and 57% diabetics. Both higher serum PTH level and higher protein intake were associated with higher risk of hyperphosphatemia in dialysis patients. Compared with patients with PTH level 150–<300 pg/ml and nPCR level 1.0–<1.2 g/kg/day, patients with iPTH>600 pg/ml and nPCR>1.2 g/kg/day had a threefold higher risk of hyperphosphatemia (OR: 3.17, 95% CI: 2.69–3.75). Hyperphosphatemia is associated with both higher dietary protein intake and higher serum PTH level in maintenance hemodialysis patients. Worsening or resistant hyperphosphatemia may be an under-appreciated consequence of secondary hyperparathyroidism independent of dietary phosphorus load. Management of hyperphosphatemia should include diligent correction of hyper-parathyroidism while maintaining adequate intake of high protein foods with low phosphorus content.

Relationship between different protein intake recommendations with muscle mass and muscle strength

Objective The purpose of the present study was to examine the relationship between two different levels of protein intake (0.8 vs.1.2 g/kg body weight/day) with muscle mass and muscle strength.Method Seventy-two postmenopausal women were recruited. Body composition (bioelectrical impedance analysis), muscle strength (dynamometer), energy metabolism (indirect calorimetry) and dietary intake (dietary journal) were measured. We divided the women into two groups. Women with a protein intake of ≥ 1.2 g/kg body weight/day were placed in the Protein ≥ 1.2 group (n = 35), whereas women with a protein intake of 0.8–1.19 g/kg body weight/day were categorized in the Protein 0.8–1.19 group (n = 32).Results No significant difference was observed between groups for age, height, skeletal muscle mass, resting energy expenditure, total energy expenditure, carbohydrate and lipid intake. Significant differences between groups were observed for body mass index (p < 0.001), fat mass (p < 0.001) and muscle strength (hand grip and knee extensors) (p < 0.001). More specifically, the Protein ≥ 1.2 group presented a higher muscle strength as well as a lower body mass index and fat mass compared to the Protein 0.8–1.19 group. In addition, the group with a protein intake of ≥ 1.2 g/kg body weight/day presented significantly higher energy intake (p = 0.002), and essential (p < 0.001) and non-essential (p < 0.001) amino acid intake. Interestingly, when muscle strength was adjusted for essential or non-essential amino acids, differences in muscle strength persisted.Conclusion The present study indicates higher levels of muscle strength in postmenopausal women with a protein intake of ≥ 1.2 g/kg body weight/day compared to 0.8–1.19 g/kg body weight/day despite no differences in muscle mass.

Associations of serum insulin-like growth factor-I and insulin-like growth factor-binding protein 3 levels with biomarker-calibrated protein, dairy product and milk intake in the Women's Health Initiative

It is well established that protein-energy malnutrition decreases serum insulin-like growth factor (IGF)-I levels, and supplementation of 30 g of whey protein daily has been shown to increase serum IGF-I levels by 8 % after 2 years in a clinical trial. Cohort studies provide the opportunity to assess associations between dietary protein intake and IGF axis protein levels under more typical eating conditions. In the present study, we assessed the associations of circulating IGF axis protein levels (ELISA, Diagnostic Systems Laboratories) with total biomarker-calibrated protein intake, as well as with dairy product and milk intake, among postmenopausal women enrolled in the Women's Health Initiative (n 747). Analyses were carried out using multivariate linear regression models that adjusted for age, BMI, race/ethnicity, education, biomarker-calibrated energy intake, alcohol intake, smoking, physical activity and hormone therapy use. There was a positive association between milk intake and free IGF-I levels. A three-serving increase in milk intake per d (approximately 30 g of protein) was associated with an estimated average 18·6 % higher increase in free IGF-I levels (95 % CI 0·9, 39·3 %). However, total IGF-I and insulin-like growth factor-binding protein 3 (IGFBP-3) levels were not associated with milk consumption and nor were there associations between biomarker-calibrated protein intake, biomarker-calibrated energy intake, and free IGF-I, total IGF-I or IGFBP-3 levels. The findings of the present study carried out in postmenopausal women are consistent with clinical trial data suggesting a specific relationship between milk consumption and serum IGF-I levels, although in the present study this association was only statistically significant for free, but not total, IGF-I or IGFBP-3 levels.

“Fast proteins” with a unique essential amino acid content as an optimal nutrition in the elderly: Growing evidence

Adequate protein intake is crucial to maintain body protein content in elderly subjects, but quality of dietary proteins should be also considered since amino acid composition and rate of protein digestion modulate amino acid availability. This study investigates whether the efficacy of optimal protein intake levels for protein retention in the elderly is influenced by protein quality. We investigated the effect of a 10-day adequate-protein (AP) or high-protein (HP) diet together with the protein source as caseins (CAS) or soluble milk proteins (PRO) on whole-body (WB) protein synthesis (PS) and protein breakdown (PB) in 4 groups of healthy elderly men (mean ± SEM: 71.8 ± 24.4 yr). The study consisted of two periods of 4 h each: a post-absorptive period and a postprandial period. The fed state was defined by consumption every 20 min and for 4 h, of either 15 g or 30 g of PRO or CAS. Steady-state WB and splanchnic leucine kinetics were measured using a continuous infusion of L-[1-13C]leucine in the postabsorptive state and L-[1-13C]leucine infusion plus oral L-[5,5,5-2H3]leucine in the postprandial state. WB PS was stimulated by feeding only with HP diets, whereas WB PB corrected for splanchnic extraction showed a similar pattern of post-feeding decrease in all groups. Consequently, net leucine balance was greater in the postprandial state after HP meals than after AP meals, with PRO meals leading to a better postprandial leucine balance (3.63 ± 0.16 μmol kg FFM(-1) min(-1)vs. 2.77 ± 0.21 μmol kg FFM(-1) min(-1) for PRO HP and CAS HP, respectively; P = 0.005). Postprandial protein retention was better improved in elderly men by an increase in protein intake when the protein supplementation was provided as fast-digesting proteins that induce high leucine availability.

Evaluation of the Protein Requirement in Chinese Young Adults Using the Indicator Amino Acid Oxidation Technique

ObjectiveTo accurately calculate the protein requirements in Chinese young adults using the indicator amino acid oxidation technique. MethodsNine women and ten men received a restricted daily level of protein intake (0.75, 0.82, 0.89, 0.97, and 1.05 g/kg), along with L-[1-13C]-leucine. Subjects' protein requirement was determined by a biphasic linear regression crossover analysis of F13CO2 data. In doing so, a breakpoint at the minimal rate of appearance of 13CO2 expiration specific to each level of dietary protein was identified. This trial was registered with the Chinese clinical trial registry as ChiCTR-ONC-11001407. ResultsThe Estimated Average Requirement (EAR) and the Recommended Nutrient Intake (RNI) of protein for healthy Chinese young adults were determined to be 0.87 and 0.98 g/(kg·d), respectively, based on the indicator amino acid oxidation technique. ConclusionThe EAR and RNI of mixed protein are 5% and 16% that are lower than the current proposed EAR and RNI (0.92 and 1.16 g/(kg·d), respectively), as determined by the nitrogen balance method. The respective EAR and RNI recommendations of 0.87 and 0.98 g/(kg·d) of mixed protein are estimated to be reasonable and suitable for Chinese young adults.

Protein intake in type 1 diabetes

Protein intake in type 1 diabetes

The mean dietary protein intake at different stages of chronic kidney disease is higher than current guidelines

The actual dietary protein intake of adults without and with different stages of chronic kidney disease is not known. To evaluate this we performed cross-sectional analyses of 16,872 adults (20 years of age and older) participating in the National Health and Nutrition Examination Survey 2001-2008 who completed a dietary interview by stage of kidney disease. Dietary protein intake was assessed from 24-h recall systematically collected using the Automated Multiple Pass Method. Complex survey analyses were used to derive population estimates of dietary protein intake at each stage of chronic kidney disease. Using dietary protein intake of adults without chronic kidney disease as the comparator, and after adjusting for age, the mean dietary protein intake was 1.30 g/kg ideal body weight/day (g/kgIBW/d) and was not different from stage 1 or stage 2 (1.28 and 1.25 g/kgIBW/d, respectively), but was significantly different in stage 3 and stage 4 (1.22 and 1.13 g/kgIBW/d, respectively). These mean values appear to be above the Institute of Medicine requirements for healthy adults and the NKF-KDOQI guidelines for stages 3 and 4 chronic kidney disease. Thus, the mean dietary protein intake is higher than current guidelines, even after adjusting for age.