High Protein Group Research Articles

Refractory diet-dependent changes in neural microstructure: Implications for microstructural endophenotypes of neurologic and psychiatric disease

Alterations in gut microbiome populations via dietary manipulation have been shown to induce diet-dependent changes in white matter microstructure. The purpose of this study is to examine the durability of these diet-induced microstructural alterations. We implemented a crossover experimental design where post-weaned male rats were assigned to one of four experimental diets. Following the administration of experimental diets and again following crossover and resumption of a normal diet, brains were imaged ex-vivo with diffusion tensor imaging. Following standard image preprocessing, tract-based spatial statistics and region-of-interest measurements were then calculated for all diffusion tensor indices. Voxel-wise differences in FA were identified in the high fat diet group when compared to animals receiving a control diet. Following crossover, there were new voxel-wise changes in both FA and TR that do not correspond to the regions previously identified. Animals crossed over from the high fiber diet demonstrate widespread and global changes in the diffusion tensor that stand in stark contrast to the minimal changes identified before crossover. While no significant differences between any of the diffusion metrics were identified in the high protein group before crossover, statistically significant decreased RD values were observed following resumption of a normal diet. Diet-induced changes in neural microstructure are durable changes that are unrecoverable following the resumption of a normal diet. We further show that in certain experimental diets, resumption of a normal diet can lead to further marked and unanticipated changes in white matter microstructure.

Dietary Protein Deficit and Deregulated Autophagy: A New Clinico-diagnostic Perspective in Pathogenesis of Early Aging, Skin, and Hair Disorders.

Background:Diet has an important role to play in the well-being of human body.Aims:The study intends to establish the “hypothesis of conscious, selective, and self-destruction i.e., deregulated autophagy of skin and hair in low dietary protein scenario” by determining the facial profile, clinical presentation, and histopathological correlation of deficient protein intake and missing of meals in a tertiary care aesthetic skin institute.Methods:A total of 98 patients of skin- and hair-related complaints were enrolled in the study and a histopathological correlation was established by skin and scalp biopsies in high and low protein groups.Results:A significant number of subjects (68.4%) were taking less than half of the recommended daily allowance of proteins and faced problems like hair fall, acne, pigmentation, vitiligo, hirsutism, melasma, and premature aging. Subjects missing breakfast were found to have hypothyroidism, diffuse hairfall, autoimmune disorders like vitiligo, lichen planus, and alopecia areata. Histopathological images from submental area showed loose and fragmented collagen in high carbohydrate group in comparison to high protein group where thick, uniformly stained collagen bundles were found in dermis. Histopathology of scalp tissue showed chronic perifollicular inflammatory infiltrate and fibrosis in high carbohydrate group which was absent in histopathology specimen of high protein group. Patients taking early and nutrient-rich breakfast had higher mean protein intakes and less severe skin and hair problems suggesting a role of circadian rhythm as well.Conclusion:Dietary protein adequacy and early breakfast have significant role in preventing self-destruction or deregulated autophagy in trichology and cosmetic dermatology and may prevent various autoimmune, inflammatory, and metabolic diseases.

Impact of a high-protein diet during lactation on milk composition and offspring in a pig model.

Early postnatal nutrition not only holds relevance to infant growth, but also determines the risk of developing obesity and chronic diseases such as diabetes type 2 and cardiovascular diseases in adulthood. It is suggested that a high-protein (HP) diet in early childhood can predispose children to obesity. However, data concerning possible alterations in milk composition and the development of the offspring in response to a maternal HP diet are currently not available. To address this question, we conducted a study using pigs as a model organism. At parturition, sows were assigned to two experimental groups. During lactation, the control group received a diet with a protein content of 16%, whereas the diet of the HP group contained 30% protein. After 28 days of lactation, samples were taken from sows and piglets for the quantification of free amino acids and other metabolites and for histology. Serum and milk urea showed the most marked differences between the two groups of sows, whereas serum urea concentration in piglets did not differ. Here, we found that the intake of an HP diet changed a series of metabolites in sows, but had only small effects on milk composition and virtually no effects on growth in the offspring. Interestingly, maternal protein intake during lactation shapes the microbiome of the offspring. From our current study, we conclude that even a very high maternal protein intake throughout lactation has no impact on growth and health parameters of the offspring.

Increased urinary exosomal microRNAs in children with idiopathic nephrotic syndrome.

BackgroundUrinary exosomal miRNAs are gaining increasing attention for their potential as ideal non-invasive biomarkers for kidney diseases; however, little is known about their diagnostic ability for paediatric nephrotic syndrome (NS). This study explored the clinical value of urinary exosomal miRNAs for paediatric idiopathic NS.MethodsUrine samples were collected from 129 NS children and 126 age−/sex-matched healthy controls. The miRNA profile of urinary exosomes was analysed by high-throughput Illumina sequencing via synthesis (SBS) technology followed by verification with a quantitative reverse-transcription polymerase chain reaction (RT-qPCR) assay arranged in two independent cohorts. Additionally, paired urine samples from 65 of these patients were collected before and after treatment.FindingsThe Illumina SBS identified 30 markedly increased urinary exosomal miRNAs in NS children compared with controls (≥ 5-fold, P < .05). Fifteen miRNAs were selected for further investigation, of which 5 (miR-194-5p, miR-146b-5p, miR-378a-3p, miR-23b-3p and miR-30a-5p) were verified by RT-qPCR to be significantly and steadily increased in NS (> 3-fold, P < .01) and markedly reduced during the clinical remission period (P < .001). Moreover, the concentrations of miR-194-5p and miR-23b-3p were significantly positively correlated with the urine protein content and were markedly higher in the high urine protein group than in the low urine protein group (P < .001 and P < .01, respectively).InterpretationsWe identified 5 altered urinary exosomal miRNAs in NS children with disease progression and treatment. These urinary exosomal miRNAs could be promising and non-invasive potential biomarker candidates for diagnosing, monitoring and stratifying paediatric NS.FundNational Natural Science Foundation of China; Fund of State Key Laboratory of Analytical Chemistry for Life Science; National Basic Research Programme of China; Foundation of Jiangsu Provincial Medical Youth Talent.

Association of protein intake with the outcomes of critically ill patients: a post hoc analysis of the PermiT trial

The optimal amount of protein intake in critically ill patients is uncertain. In this post hoc analysis of the PermiT (Permissive Underfeeding vs. Target Enteral Feeding in Adult Critically Ill Patients) trial, we tested the hypothesis that higher total protein intake was associated with lower 90-d mortality and improved protein biomarkers in critically ill patients. In this post hoc analysis of the PermiT trial, we included patients who received enteral feeding for ≥3 consecutive days. Using the median protein intake of the cohort as a cutoff, patients were categorized into 2 groups: a higher-protein group (>0.80 g · kg-1 · d-1) and a lower-protein group (≤0.80 g · kg-1 · d-1). We developed a propensity score for receiving higher protein. Primary outcome was 90-d mortality. We also compared serial values of prealbumin, transferrin, 24-h urinary nitrogen, and 24-h nitrogen balance on days 1, 7, and 14. Among the 729 patients included in this analysis, the average protein intake was 0.8±0.3 g · kg-1 · d-1 [1.0±0.2 g · kg-1 · d-1 in the higher-protein group (n=365) and 0.6±0.2 g · kg-1 · d-1 in the lower-protein group (n=364); P<0.0001]. There was no difference in 90-d mortality between the 2 groups [88/364 (24.2%) compared with 94/363 (25.9%), propensity score-adjusted OR: 0.80; 95% CI: 0.56, 1.16; P=0.24]. Higher protein intake was associated with an increase in 24-h urea nitrogen excretion compared with lower protein intake, but without a significant change in prealbumin, transferrin, or 24-h nitrogen balance. In the PermiT trial, a moderate difference in protein intake was not associated with lower mortality. Higher protein intake was associated with increased nitrogen excretion in the urine without a corresponding change in prealbumin, transferrin, or nitrogen balance. Protein intake needs to be tested in adequately powered randomized controlled trials targeting larger differences in protein intake in high-risk populations.

The low protein diet affects the nonspecific inflammatory response of middle-aged and old mice through mTOR.

To explore the effect of low protein diet on nonspecific inflammatory changes in mice during aging and related mechanisms. Thirty-two 14-month-old female KM mice were randomly divided into 4 groups: control group, low protein group, high protein group, high protein + rapamycin group. Hematoxylin-eosin (HE) staining was performed to observe the pathological changes of the liver. Immunohistochemistry of liver sections was performed to detect the expression of CD68 protein. HE staining of colon sections was performed to observe intestinal lymphocyte infiltration. The percentage of spleen CD4+ T and CD8+ T cells was detected by flow cytometry. The mTOR expression in the liver was detected by Western blot and immunohistochemistry. Compared with the control group, HE staining of liver tissue sections in high-protein group showed the cytoplasm of hepatocytes was loose and disordered, and the hepatic sinus was significantly expanded. Immunohistochemistry of the liver showed a significant increase in CD68 protein expression. Colorectal HE staining showed extensive lymphocyte infiltration. The number of CD4+ T and CD8+ T cells in spleen flow cytometry was significantly decreased (*p < 0.05). Western blot and immunohistochemistry detected a significant increase in mTOR expression in the liver (*p < 0.05, *p < 0.05). In the High Protein+Rapamycin group and Low-protein group, the time-dependent changes were reduced, the numbers of CD4+ T cell and CD8+ T cell in the spleen were significantly increased (*p < 0.05) and the expression of mTOR was significantly reduced (*p < 0.05). Low-protein diet is beneficial for delaying the non-specific inflammatory changes of liver and intestines in middle-aged and aged mice, and this effect may be achieved through down-regulation of mTOR.

Elevated TRIM23 expression predicts poor prognosis in Chinese gastric cancer

The gene TRIM23 (tripartite motif containing 23) is a member of the tripartite motif (TRIM) family whose expression putatively participates in many pathophysiological processes. Nonetheless, the role of TRIM23 in gastric cancer (GC) remains uncertain. Our study evaluated the expression of TRIM23 in GC tissues and cell lines, and investigated an association between TRIM23 and survival. In the present study, our results demonstrated that TRIM23 mRNA and protein were frequently over-expressed in GC cell lines and GC tissues. High level of TRIM23 protein correlated with tumor size, tumor-node-metastasis (TNM) stage, depth of invasion, lymph node metastasis (LNM), tumor differentiation, and nerve invasion. Compared with the low TRIM23 protein group, the high TRIM23 protein group was significantly associated with worse prognosis of GC patients. Consistently, the KM-plot database suggested that high TRIM23 mRNA expression was also linked to a poor prognosis in GC patients both in positive and negative subgroups of human epidermal growth factor receptor 2 (HER2). But in the HER2 positive subgroup, the advantages of the low TRIM23 expression on overall survival were much more statistically significant. The univariate analysis indicated that TRIM23 expression correlated with overall survival. The multivariate analysis showed that independent factors of prognosis in GC were lymph node metastasis, vascular invasion, and depth of invasion. In summary, TRIM23 may be associated with progression of GC, and may be considered a therapeutic target for GC patients.

Effect of Lower Versus Higher Protein Content in Infant Formula Through the First Year on Body Composition from 1 to 6 Years: Follow-Up of a Randomized Clinical Trial.

The objective of this study was to investigate the effect of lower protein (LP) versus higher protein (HP) content in infant formula on body composition from 3 months to 6 years. In a multicenter, double-blind European trial, healthy infants (N = 1,090) were randomly assigned to different protein content formulas (upper [HP] and lower [LP] limits of the European Union regulations in 2001) during the first year; breastfed infants (N = 588) were recruited for reference values. Weight, height, and triceps and subscapular skinfold (SF) thickness were measured repeatedly (N = 650 at 6 years), and body composition was estimated (Slaughter). The 99th percentile of fat mass index reference data were used to assess excess body fat at 6 years. At 2 and 6 years, the study observed greater sum of SFs (Δ 2 years: 0.5 mm, P = 0.026, Δ 6 years: 0.6 mm, P = 0.045), fat mass index (Δ 2 years: 0.12 kg/m², P = 0.008, Δ 6 years: 0.15 kg/m², P = 0.011), and fat-free mass index (Δ 2 years: 0.17 kg/m², P = 0.003, Δ 6 years: 0.18 kg/m², P = 0.010) in the HP group compared with the LP group. At 6 years, the HP group had a twofold higher risk than the LP group for excess body fat (adjusted odds ratio: 2.13, P = 0.019). Infant formula with HP levels induced greater fat mass in children from 2 to 6 years. Lowering the protein content of infant formula may result in a healthier body composition in early childhood.

The Effect of Increasing the Protein Content of Human Milk Fortifier to 1.8 g/100 mL on Growth in Preterm Infants: A Randomised Controlled Trial.

The aim of this study was to assess the effect of feeding high protein human milk fortifier (HMF) on growth in preterm infants. In this single-centre randomised trial, 60 infants born 28–32 weeks’ gestation were randomised to receive a higher protein HMF providing 1.8 g protein (n = 31) or standard HMF providing 1 g protein per 100 mL expressed breast milk (EBM) (n = 29). The primary outcome was rate of weight gain. Baseline characteristics were similar between groups. There was no difference between high and standard HMF groups for weight gain (mean difference (MD) −14 g/week; 95% CI −32, 4; p = 0.12), length gain (MD −0.01 cm/week; 95% CI −0.06, 0.03; p = 0.45) or head circumference gain (MD 0.007 cm/week; 95% CI −0.05, 0.06; p = 0.79), despite achieving a 0.7 g/kg/day increase in protein intake in the high protein group. Infants in the high protein group had a higher proportion of lean body mass at trial entry; however, there was no group by time effect on lean mass gains over the study. Increasing HMF protein content to 1.8 g per 100 mL EBM does not improve growth in preterm infants born 28–32 weeks’ gestation.

Effect of protein intake beyond habitual intakes following resistance training on cardiometabolic risk disease parameters in pre-conditioned older women.

The aim of this study was to analyze the effects of higher protein (HP) intake associated with resistance training (RT) on parameters of cardiometabolic risk disease (CMR). A randomized, double-blind and placebo-controlled design was conducted. Thirty-two pre-conditioned older women were randomized in two groups to receive 35 g of protein (high protein group - HP) or 35 g of placebo (low protein group - LP) after training sessions. The RT program was carried out over 12 weeks, 3 days per week and 3 sets of 8-12 repetitions. Body composition (whole-body dual-energy X-ray absorptiometry), blood samples, anthropometric measurements and dietary intake were performed at pre- and post-intervention. There was a significant group-by-time interaction (P < 0.05) for lean soft tissue (LST), total cholesterol/high density lipoprotein ratio (TC/HDL) and volume of load (VL), in which HP group presented greater improvements when compared to LP group (LST: +3.8% vs +2.0%; TC/HDL: -11.8% vs -2.9%; VL: 45.4% vs 35.4%). A time effect was found for HDL, LDL, Triglycerides (TGC), total cholesterol (TC), low density lipoprotein/HDL ratio (LDL/HDL) and C-reactive protein (CRP) (HDL: +6.7% vs +6.3%; LDL: -6.8% vs +0.9%; TGC: -2.0% vs -1.2%; TC: -2.8% vs +0.5%; LDL/HDL: -11.5 vs -6.9%; CRP: -8.6% vs -11.5%) in which both groups improved their scores without statistical differences between them. No effect was found for waist circumference. Increased dietary protein intake, achieved by whey protein supplementation, when associated with RT promotes greater gains on LST and VL, and a reduction on TC/HDL ratio in pre-conditioned older women.

Effect of increased enteral protein intake on plasma and urinary urea concentrations in preterm infants born at

BackgroundFeeding breast milk is associated with reduced morbidity and mortality, as well as improved neurodevelopmental outcome but does not meet the high nutritional requirements of preterm infants. Both plasma and urinary urea concentrations represent amino acid oxidation and low concentrations may indicate insufficient protein supply.This study assesses the effect of different levels of enteral protein on plasma and urinary urea concentrations and determines if the urinary urea-creatinine ratio provides reliable information about the protein status of preterm infants.MethodsSixty preterm infants (birthweight < 1500 g; gestational age < 32 weeks) were enrolled in a randomized controlled trial and assigned to either a lower-protein group (median protein intake 3.7 g/kg/d) or a higher-protein group (median protein intake 4,3 g/kg/d). Half the patients in the higher-protein group received standardized supplementation with a supplement adding 1.8 g protein/100 ml milk, the other half received individual supplementation depending on the respective mother’s milk macronutrient content. Plasma urea concentration was determined in two scheduled blood samples (BS1; BS2); urinary urea and creatinine concentrations in weekly spot urine samples.ResultsThe higher-protein group showed higher plasma urea concentrations in both BS1 and BS2 and a higher urinary urea-creatinine-ratio in week 3 and 5–7 compared to the lower-protein group. In addition, a highly positive correlation between plasma urea concentrations and the urinary urea-creatinine-ratio (p < 0.0001) and between actual protein intake and plasma urea concentrations and the urinary urea-creatinine-ratio (both p < 0.0001) was shown.ConclusionsThe urinary urea-creatinine-ratio, just like plasma urea concentrations, may help to estimate actual protein supply, absorption and oxidation in preterm infants and, additionally, can be determined non-invasively. Further investigations are needed to determine reliable cut-off values of urinary urea concentrations to ensure appropriate protein intake.Trial registrationClinicaltrials.gov; NCT01773902 registered 15 January 2013, retrospectively registered.

Comparison of hs-CRP level between low calorie high protein to standard protein diet in obese individuals with weight cycling - a randomised trial

Background: Obesity is associated with various health problems. Low-grade inflammation is a condition found in obese people and contributes to the development of various diseases. The objective of this study was to compare the effects of calorie restriction diet with high-protein (HP) or standard protein (SP) to inflammation marker (hs-CRP) in obese individuals with weight cycling. Methods: 61 healthy obese men and women (25 – 49 years old) with a history of weight cycling were recruited and were randomly assigned to one of the intervention groups, HP or SP groups. Both groups were suggested to reduce their daily caloric intake by 1000 kcal with regular physical activity for 56 days. Subjects in HP group were given a daily protein intake of 22-30% from total daily caloric intake, while SP group were prescribed 12-20%. Dietary consultation was conducted through daily reminder by phone and weekly counseling. The measurement of hs-CRP level was performed prior to and at the end of the intervention. Results: 54 subjects completed the program, yet due to several reasons only 32 of them were measured for hsCRP before and after completing the program, 15 from HP group and 17 from SP group. After completing the 56-day diet program, SP group experienced reduction of hs-CRP by -0.446 + 4.239, while HP underwent increase by 0.135 + 2.389. The mean difference of change in hs-CRP level between the two groups were not statistically significant (P=0.094). Conclusion: Low calorie diet with either HP or SP for 8 weeks significantly reduced body weight (P&lt;0.001) and BMI (P&lt;0.001) in healthy obese subjects but the difference of change in the hs-CRP level between them were not significant. The protein composition of a low calorie diet may not affect the inflammatory state of obese individuals with weight cycling. Trial registration number: NCT03374150

Comparison of body composition changes between low calorie high protein diet to standard protein in obese individuals with weight cycling – a randomised trial

Background:The world prevalence of obesity in adult population in 2014 was nearly 13% while in Indonesia, it has reached 32.9% in the same year. Obesity is an established risk factors for cardiovascular diseases. A large proportion of people who had succeeded to reduce body weight failed to maintain it (weight cycling). Studies were inconclusive about the best composition in the diet for such people. The purpose of this research was to evaluate the body composition changes resulted from low calorie high protein and standard protein diet programme in obese people with history of weight cycling.Methods:This is an open-randomized clinical trial of weight loss program as a part of a larger study researching the effect of low calorie high protein diet to body composition, oxidative stress, inflammation marker and metabolic syndrome in obese with weight cycling. A total of 61 adult obese men and women with history of weight cycling were recruited. Subjects were assigned to low calorie diet and were randomly distributed into two intervention groups, namely high protein group (22-30 % of total calories intake) and standard protein group (12-20%). Anthropometry and body composition data were taken at baseline and at the end of the study. Subjects were followed up to 8 weeks with daily reminder and weekly counselling.Results:Fourty five participants completed the study. There were significant reductions in in body weight and body mass index (BMI), fat mass, fat mass percentage, muscle mass, and gain in muscle mass percentage occurred in both groups (Standard protein: P&lt;0.001; High protein: P&lt;0.001 for all variables except for fat mass P= 0,001) with no difference between group (P&gt;0.05).Conclusion:Calories deficit with either high protein or standard protein for 8 weeks brought about significant reduction in body composition

High protein consumption in trained women: bad to the bone?

BackgroundIt has been posited that the consumption of extra protein (> 0.8 g/kg/d) may be deleterious to bone mineral content. However, there is no direct evidence to show that consuming a high-protein diet results in a demineralization of the skeleton. Thus, the primary endpoint of this randomized controlled trial was to determine if a high-protein diet affected various parameters of whole body and lumbar bone mineral content in exercise-trained women.MethodsTwenty-four women volunteered for this 6-month investigation (n = 12 control, n = 12 high-protein). The control group was instructed to consume their habitual diet; however, the high-protein group was instructed to consume ≥2.2 g of protein per kilogram body weight daily (g/kg/d). Body composition was assessed via dual-energy x-ray absorptiometry (DXA). Subjects were instructed to keep a food diary via the mobile app MyFitnessPal®. Exercise or activity level was not controlled. Subjects were asked to maintain their current levels of exercise.ResultsDuring the 6-month treatment period, there was a significant difference in protein intake between the control and high-protein groups (mean±SD; control: 1.5±0.3, high-protein: 2.8±1.1 g/kg/d); however, there were no differences in the consumption total calories, carbohydrate or fat. Whole body bone mineral density did not change in the control (pre: 1.22±0.08, post: 1.22±0.09 g/cm2) or high-protein group (pre: 1.25±0.11, post: 1.24±0.10 g/cm2). Similarly, lumbar bone mineral density did not change in the control (pre: 1.08±0.16, post: 1.05±0.13 g/cm2) or high-protein group (pre: 1.07±0.11, post: 1.08±0.12 g/cm2). In addition, there were no changes in whole body or lumbar T-Scores in either group. Furthermore, there were no changes in fat mass or lean body mass.ConclusionDespite an 87% higher protein intake (high-protein versus control), 6 months of a high-protein diet had no effect on whole body bone mineral density, lumbar bone mineral density, T-scores, lean body mass or fat mass.

High protein diets do not affect anthropometric indexes and cardiometabolic risk factors among children with excess weight: A randomized controlled trial.

Introduction: Limited information exists regarding the effects of high protein (HP) diets on cardiovascular disease (CVD) risk factors among overweight and obese children. Our aim was to determine the effects of an HP diet on anthropometric indexes and CVD risk factors among overweight and obese children. Methods: In a parallel randomized controlled trial, we recruited 50 overweight and obese children, aged 6-11 years, for a 10 week HP or control diet (protein, carbohydrate, fat: 25%, 45%, 30% in the HP diet vs. 15%, 55%, 30% in the control diet, respectively). Fasting blood glucose (FBG) serum insulin levels, lipid profiles, systolic and diastolic blood pressure (SBP and DBP), and anthropometric measurements were assessed using standard guidelines. Results: 86% of children completed the trial. Percent changes (PC) for anthropometric and biochemical variables were not significantly different between the two groups. The PC of serum triglyceride (TG) level was significantly decreased in the HP group compared to in the control group (PC: -10.16±4.30% vs.12.11±7.80%; P = 0.01) in the crude model, but not in the adjusted model. For other variables, we did not find any significant differences between the HP group and the controls. Conclusion: In the present study, we did not find any significant effect of adherence to an HP diet in improving anthropometric measurements or other CVD risk factors among obese and overweight children.

Differential mGluR5 expression in response to the same stress causes individually adapted hippocampal network activity

Individual differences in stress vulnerability and resilience have been observed even within a single cohort of inbred rats or mice. Stress phenotypes are typically quantified as changes in the behavior of experimental animals, which is the outcome of altered electrical activity of the brain network. Although mGluR5 is associated with individual vulnerability to stress and can act as a sensitive biomarker of stress adaptation, our understanding of mGluR5-dependent modifications to neural network activities in vivo remains limited. Here, we examined individual rats for changes in hippocampal mGluR5 expression induced by restraint stress and found that these changes cause accompanying changes in hippocampal electroencephalography (EEG) activity. We found six days of restraint stress caused variable changes in hippocampal mGluR5 expression, ranging from 20.9% to 210.7% of the control group. The low mGluR5 protein group (LE) showed increased methylation of the mGluR5 CpG island, reduced mGluR5 mRNA levels, and unaltered basal EEG theta spectral power between stress day 1 and 6. In contrast, the high mGluR5 protein group (HE) showed reduced methylation of CpG sites, increased mGluR5 mRNA expression, and reduced basal theta spectral power on stress day 6. We also found that injection of lentiviruses expressing mGluR5-specific shRNAs into the hippocampus rescued this reduction in baseline theta power in HE rats. These data suggest a causal relationship between individual differences in the changes in hippocampal mGluR5 expression induced by repetitive restraint stress and the accompanying changes in ensemble neural activity in the hippocampus.

Use of Novel High-Protein Functional Food Products as Part of a Calorie-Restricted Diet to Reduce Insulin Resistance and Increase Lean Body Mass in Adults: A Randomized Controlled Trial.

Significant reductions in insulin resistance (IR) can be achieved by either calorie restriction or by the increase of lean mass. However, calorie restriction usually results in significant loss of lean mass. A 6-week randomized controlled feeding trial was conducted to determine if a calorie-restricted, high-protein diet (~125 g protein/day consumed evenly throughout the day) using novel functional foods would be more successful for reducing IR in comparison to a conventional diet (~80 g protein/day) with a similar level of calorie restriction. Healthy adults (age 20–75 years; body mass index, 20–42 kg/m2) with raised triglyceride/high-density lipoprotein ratios were randomly assigned to the control group (CON: test foods prepared using gluten-free commercial pasta and cereal) or to the high-protein group (HPR: test foods prepared using novel high-protein pasta and cereal both rich in wheat gluten). Mean weight loss did not differ between groups (−2.7 ± 2.6 and −3.2 ± 3.0 kg for CON (n = 11) and HPR (n = 10) respectively, p = 0.801); however, the 6-week change in fat-free mass (FFM) differed significantly between groups (−0.5 ± 1.5 and +1.5 ± 3.8 kg for CON and HPR respectively, p = 0.008). IR improved in HPR vs. CON participants (homeostasis model assessment-estimated insulin resistance [HOMAIR] change: −1.7 ± 1.4 and −0.7 ± 0.7 respectively; p = 0.020). The change in HOMA-IR was related to the change in FFM among participants (r = −0.511, p = 0.021). Thus, a high-protein diet using novel functional foods combined with modest calorie restriction was 140% more effective for reducing HOMA-IR in healthy adults compared to a lower protein, standard diet with an equal level of calorie restriction.

Protein delivery and clinical outcomes in the critically ill: a systematic review and meta-analysis

Objectives: Protein is a fundamental component of critical care nutrition, but there has been uncertainty about the optimal amount. We undertook this systematic review and meta-analysis to examine the relationship between delivered protein and mortality in randomised controlled trials (RCTs) of nutritional interventions involving critically ill adults. Secondary outcomes included the effect of protein dose on lengths of stay, mechanical ventilation and incidence of infections.Methods: We reviewed the relevant English-language literature published between 1966 and 2015 and identified RCTs comparing different strategies of nutritional support lasting at least 48 hours in critically ill adults. Articles were included if mortality was reported and the difference in delivered protein between interventions was significant (P < 0.05). We calculated summary estimates for mortality as odds ratios (ORs) with 95% confidence intervals (CIs) using a random-effects estimator, and we used meta-regression to assess the effect of delivered protein on mortality.Results: From 3016 assessed records, 357 full-text articles were reviewed and 14 studies, investigating various interventions and routes of nutrition and comprising 3238 patients, were included. The mean protein delivered was 42.95 g/day (SD, 20.45 g/day) or 0.67 g//kg/day (SD, 0.38 g/kg/day) in patients receiving less protein, and 67.15 g/day (SD, 28.47 g/day) or 1.02 g/kg/day (SD, 0.42 g/kg/day) in the higher protein group. Provision of less protein did not influence mortality risk (pooled OR, 0.935; 95% CI, 0.716 –1.219; P = 0.618; I2 = 48.2%). Meta-regression analysis did not show a relationship between mean daily protein delivered and mortality (P = 0.433; I2 = 50.18%). There were no differences between groups in any secondary outcomes.Conclusions: Delivery of varying amounts of nutritional protein was not associated with any effect on mortality.

Effect of a high protein diet and/or resistance exercise on the preservation of fat free mass during weight loss in overweight and obese older adults: a randomized controlled trial

BackgroundIntentional weight loss in obese older adults is a risk factor for accelerated muscle mass loss. We investigated whether a high protein diet and/or resistance exercise preserves fat free mass (FFM) during weight loss in overweight and obese older adults.MethodsWe included 100 overweight and obese adults (55–80 year) in a randomized controlled trial (RCT) with a 2 × 2 factorial design and intention-to-treat analysis. During a 10-week weight loss program all subjects followed a hypocaloric diet. Subjects were randomly allocated to either a high protein (1.3 g/kg body weight) or normal protein diet (0.8 g/kg), with or without a resistance exercise program 3 times/week. FFM was assessed by air displacement plethysmography.ResultsAt baseline, mean (±SD) BMI was 32 ± 4 kg/m2. During intervention, protein intake was 1.13 ± 0.35 g/kg in the high protein groups vs. 0.98 ± 0.29 in the normal protein groups, which reflects a 16.3 ± 5.2 g/d higher protein intake in the high protein groups. Both high protein diet and exercise did not significantly affect change in body weight, FFM and fat mass (FM). No significant protein*exercise interaction effect was observed for FFM. However, within-group analysis showed that high protein in combination with exercise significantly increased FFM (+0.6 ± 1.3 kg, p = 0.011).ConclusionA high protein diet, though lower than targeted, did not significantly affect changes in FFM during modest weight loss in older overweight and obese adults. There was no significant interaction between the high protein diet and resistance exercise for change in FFM. However, only the group with the combined intervention of high protein diet and resistance exercise significantly increased in FFM.Trial registrationDutch Trial Register, number NTR4556, date 05-01-2014.

Protein Supplementation of a High-Carbohydrate Diet during Resistance Training Enhances Muscle Mass and Function by Increasing Essential Amino Acids

Objective: Previous studies have presented the effects of carbohydrate and protein intake using a single food or supplement. However, little knowledge is available regarding the long-term effects of protein diet supplementation on muscle mass and function. This study was conducted to investigate the effects of a 12-week high-intensity resistance exercise program combined with a high-carbohydrate (HCHO), high-protein (HPRO) diet on body composition, muscle function, anabolic/catabolic hormones, and blood amino acid levels. Methods: This study included 27 male college students, who were divided into an HPRO group (n=12) and an HCHO group (n=15). Three to five sets of resistance exercises were performed four times a week at 75% of 1- repetition maximum for 12 weeks. Results: The weight and body fat percentage decreased in both groups after the 12-week resistance exercise, and muscle mass increased in the HPRO group. The peak torque increased in the HPRO group, and the average power increased in both the HCHO and HPRO groups, although there was no significant difference between the changes in both groups. However, the testosterone level and the ratio of testosterone to cortisol increased in the HCHO group, and the changes were significantly different between the groups. The blood essential amino acid (EAA) and non-essential amino acid levels showed a time × group effect. Conclusion: Protein supplementation of a high-carbohydrate diet during resistance training may enhance body composition and muscle mass and function by increasing the blood EAA levels. Therefore, considering that Asians tend to consume high-carbohydrate diets, a diet with slightly less carbohydrate and increased protein may be more effective for increased muscle strength and mass during training.