Dietary Protein Intake Research Articles

Associations between High Protein Intake, Linear Growth, and Stunting in Children and Adolescents: A Cross-Sectional Study.

Childhood and adolescence are critical periods for linear growth and preventing stunting. Current evidence indicates that dietary protein intake in children and adolescents is often two to three times higher than the recommendations in many regions worldwide. However, few studies have focused on the association between high protein intake and linear growth and stunting in this population. We aim to investigate this association in children and adolescents aged 6 to 18 years in a population with relatively high protein consumption. We conducted a large cross-sectional study involving 3299 participants from Shenzhen, a modern metropolis of China. Protein intake, including total protein, animal protein, and plant protein, was evaluated by a food-frequency questionnaire and expressed as grams per kilogram of body weight per day (g·kg-1·d-1) and as a percentage of total energy intake (%E). The primary outcomes were body height and height-for-age Z score (HAZ). Generalized linear models and logistic regression analyses were employed to examine the associations between protein intake and outcomes. We also conducted stratified analyses across different genders and pubertal stages in the aforementioned associations. The mean protein intake was 1.81 g·kg-1·d-1 (17% E). After adjusting for serum calcium, zinc, vitamin D3, vitamin A levels, birth outcomes, lifestyle, and parental characteristics, each standard deviation increase of 1 in protein intake (0.64 kg-1·d-1) is found to be associated with a -5.78 cm change in body height (95% CI: -6.12, -5.45) and a -0.79 change in HAZ (95% CI: -0.84, -0.74). Consistent results were observed when protein intake was expressed as %E or specifically as animal or plant protein. Moreover, the relationship between protein intake and linear growth remained consistent across genders in different pubertal stages, similar to that of the overall participants. Our findings highlight the potential hazards of high protein intake on linear growth in children and adolescents. Caution should be exercised when promoting increased protein consumption in children and adolescents who already have a high intake of protein.

Association between dietary protein intake, diet quality and diversity, and obesity among women of reproductive age in Kersa, Ethiopia.

In Ethiopia, there is limited evidence on the effect of dietary protein intake on women's body mass index. Therefore, this study investigated the association between dietary protein intake, diet quality, and overweight and obesity. A cross-sectional study was conducted among 897 women of reproductive age. Food frequency questionnaires were used to assess 7-day dietary intake. It was converted into protein and other macro-nutrient intakes, Minimum Dietary Diversity for Women, and Global Dietary Quality Score. Body Mass Index (BMI) of overweight & obese women were defined as ≥25 kg/m2. An adjusted odds ratio with a 95% confidence interval (in a multivariate logistic regression model) was used to determine the strength of the association between BMI and dietary protein intake, adjusting for potential confounders. The median dietary protein intake was 41.3 (32.9, 52.6) grams/day or 0.8 (0.6, 1.0) grams/kilogram of body weight/day. The prevalence of overweight and obesity was 7.5% (n = 67). Only 220 (24.5%) women could meet the recommended minimum dietary diversity of five or more food groups out of 10 per day. Furthermore, only 255 (28.4%) women were found to have a low risk for nutrient adequacy. Interestingly, women who consumed moderate dietary protein had a significantly lower likelihood of being overweight or obese, with AOR of 0.21 (95% CI 0.10-0.48). Similarly, those who consumed a high amount of protein had even lower odds, with AOR of 0.03 (95% CI 0.01-0.14), compared to those who consumed a low amount of dietary protein. Age of 40-49 years (AOR = 3.33, 95% CI 1.24-8.95) compared to 18-29 years, non-farmers (AOR = 3.21, 95% CI 1.55-6.62), higher consumption of food from unhealthy groups (AOR = 1.30, 95% CI 1.05-1.61), and high fat intake (AOR = 1.06, 95% CI 1.04-1.09) were associated with overweight and obesity. The study indicated an inverse relationship between BMI and dietary protein intake. It also revealed that women who consumed foods from unhealthy or unhealthy when consumed in excessive amounts were more likely to be overweight or obese. Increasing dietary protein consumption can help reproductive-age women reduce the odds of obesity and overweight. Furthermore, community-based educational programs, policy changes, and healthcare services can support this effort.

Plasma Metabolomics of Dietary Intake of Protein-Rich Foods and Kidney Disease Progression in Children

Evidence regarding the efficacy of a low-protein diet for patients with CKD is inconsistent and recommending a low-protein diet for pediatric patients is controversial. There is also a lack of objective biomarkers of dietary intake. The purpose of this study was to identify plasma metabolites associated with dietary intake of protein and to assess whether protein-related metabolites are associated with CKD progression. Nontargeted metabolomics was conducted in plasma samples from 484 Chronic Kidney Disease in Children (CKiD) participants. Multivariable linear regression estimated the cross-sectional association between 949 known, nondrug metabolites and dietary intake of total protein, animal protein, plant protein, chicken, dairy, nuts and beans, red and processed meat, fish, and eggs, adjusting for demographic, clinical, and dietary covariates. Cox proportional hazards models assessed the prospective association between protein-related metabolites and CKD progression defined as the initiation of kidney replacement therapy or 50% eGFR reduction, adjusting for demographic and clinical covariates. One hundred and twenty-seven (26%) children experienced CKD progression during 5years of follow-up. Sixty metabolites were significantly associated with dietary protein intake. Among the 60 metabolites, 10 metabolites were significantly associated with CKD progression (animal protein: n=1, dairy: n=7, red and processed meat: n=2, nuts and beans: n=1), including one amino acid, one cofactor and vitamin, 4 lipids, 2 nucleotides, one peptide, and one xenobiotic. 1-(1-enyl-palmitoyl)-2-oleoyl-glycerophosphoethanolamine (GPE, P-16:0/18:1) was positively associated with dietary intake of red and processed meat, and a doubling of its abundance was associated with 88% higher risk of CKD progression. 3-ureidopropionate was inversely associated with dietary intake of red and processed meat, and a doubling of its abundance was associated with 48% lower risk of CKD progression. Untargeted plasma metabolomic profiling revealed metabolites associated with dietary intake of protein and CKD progression in a pediatric population.

The Relationship between Dietary Patterns, Physical Activity and Protein Intake with Dysmenorrhea in Female Students at SMPN 4 Samarinda

Dysmenorrhea is often experienced by most women during their menstrual cycle. This condition is characterized by lower abdominal pain ranging from mild to severe and accompanied by other symptoms such as nausea, vomiting, diarrhea, headaches and general discomfort. The aim of the research was to determine the relationship between diet, physical activity and protein intake with dysmenorrhea in female students at SMP Negeri 4 Samarinda. This type of research is quantitative research using a cross sectional design. The research sample was 64 class VIII students at SMPN 4 Samarinda who experienced dysmenorrhea. The research was conducted in March-April 2023. Data analysis used the chi-square test. The research results showed a relationship between physical activity level and dysmenorrhea with a p-value of 0.000 <0.05. Diet and protein intake have no relationship with dysmenorrhea because the p-value is> 0.05.

Association between nut consumption and low muscle strength among Korean adults.

Nuts are an important component of a healthy diet, but little has been known about their effects on muscle health. Therefore, this study examined the association between nut consumption and low muscle strength among Korean adults. This cross-sectional analysis was conducted using single 24-h recall and handgrip strength data from 3962 younger adults 19-39 years, 6921 middle-aged adults 40-64 years and 3961 older adults ≥65 years participated in the seventh cycle (2016-2018) of the Korea National Health and Nutrition Examination Survey. Low muscle strength was defined as handgrip strength <28 kg for men and <18 kg for women. Sex-specific OR were obtained for younger, middle-aged and older adults using multivariable logistic regression analyses. About one in four Korean adults were consuming nuts (using a culinary definition) with peanut being the most frequently consumed type. After adjustment for age, BMI, total energy intake, household income, alcohol consumption, smoking, resistance exercise, medical history and dietary protein intake, nut consumption was associated with the lower risk of low muscle strength among older adults ≥65 years (men: OR 0·55, 95 % CI (0·38, 0·79); women: OR 0·69, 95 % CI (0·51, 0·93)); however, this association was not observed among younger adults 19-39 years or middle-aged adults 40-64 years. Our results suggest that consuming nuts might be beneficial in lowering the risk of low muscle strength among Korean older adults.

Dietary protein intake and changes in muscle mass measurements in community-dwelling middle-aged and older adults: A prospective cohort study

Increasing dietary protein intake can be an efficient strategy to prevent sarcopenia. Nevertheless, due to the discrepancy in the population and their dietary pattern, evidence suggested the effects of dietary protein amount or source on sarcopenia prevention varies. This prospective cohort study investigated the correlation between dietary protein intakes or sources and changes in muscle mass measurements. Additionally, the study explored the link between dietary protein and the prevalence of sarcopenia. Participants aged 40 to 75 were from Guangzhou Nutrition and Health Study (GNHS) 2011-2013 and returned in 2014-2017. Validated 79-item food frequency questionnaires were applied to calculate the amount of total, animal, and plant protein intakes and animal-to-plant protein ratio (APR). The body composition was examined by dual-energy x-ray absorptiometry (DXA) to calculate the appendicular lean mass (ALM) and its index (ASMI). Sarcopenia was diagnosed based on the 2019 Asia Working Group of Sarcopenia's criteria. ANCOVA was utilized to compare the differences of Δ ALM and Δ ASMI across the quartiles of the dietary protein, and linear regression was employed to examine dose-response associations. Multilinear mixed-effect models were employed to evaluate whether protein intake relates to annual changes in ALM and ASMI. Multivariable logistic regressions were performed to analyze the associations between dietary protein and sarcopenia. In total, 2709 participants during the 3.2-year follow-up period were considered eligible for analysis. Higher dietary protein intakes (total, animal, plant) in both sexes could preserve more ALM and ASMI in a dose-response manner (all P-trend<0.05). The annual estimated preservations of ASMI were greater in the highest dietary protein intakes (total, animal, plant) quartile than the lowest (0.05-0.13kg/m2/y, all P<0.05). In women, the risk of sarcopenia was reduced by 35%-50% in the highest protein intake (total, animal, plant) quartile than the lowest. The APR did not display any significant associations. Higher dietary protein intake, regardless of animal or plant sources, is associated with less muscle loss and a lower prevalence of sarcopenia in middle-aged and older Chinese, particularly women. NCT03179657.

Association between total and animal proteins with risk of fracture: A systematic review and dose-response meta-analysis of cohort studies.

Previous cohort studies have indicated that consumption of total and animal proteins are related to fracture risk; however, results were inconclusive. This dose-dependent review sought to summarize the earlier evidence regarding the relation between total and animal proteins and fracture risk. We searched Scopus, PubMed, and Web of Science until July 2023 for original research articles examining the association of certain types of proteins and the incidence of all fractures in general adults. Summary relative risks (RRs) were calculated using random effects analysis to examine the relation between each certain amount (g/day) increment of total and animal protein and fracture risk. Twenty cohort studies with serious to moderate risk of bias involving 780,322 individuals were included. There was a non-statistically significant relation between intake of animal proteins and dairy products and all fracture risk. However, 43% and 5% decreased incidence of fracture was obtained with total protein (RR, 0.57; 95%CI, 0.36 to 0.93; per 100g/day) and fish (RR, 0.95; 95%CI, 0.91 to 0.99; per 15g/day) intake. Every 100g/day total and animal protein consumption and every 15g/day fish consumption were linked to 48%, 50%, and 5% lower hip fracture risk. Greater dietary animal protein intake might reduce risk of hip but not fracture at any site. We obtained a lower risk of any or hip fracture with greater total protein (per 100g/day) and fish (per 15g/day) intake. No evidence was obtained that higher intake of dairy could decrease risk of fracture.

Comparative assessment of urea, creatinine, and blood urea nitrogen in male and female patients with different age groups of chronic kidney disease in Shaheed Benazir Abad, Sindh

Chronic kidney disease (CKD) is a heterogeneous disorder that affects the structure and function of the kidney. The primary biochemical markers for diagnosis and evaluating stages of CKD include urea (Ur), blood nitrogen urea (BUN), and creatinine (Cr). In this study, we investigate three biochemical parameters such as Ur, BUN, and Cr levels in CKD patients’ gender-vice with different age groups. Blood samples (n = 300) of males and females were collected from the Biochemistry Lab, Peoples University of Medical and Health Science, Shaheed Benazirabad during the 2023 year. Blood samples (5ml) were collected from the individuals through venipuncture and centrifuged for further analysis. Reagent 1 (2-Oxoglutarate ADP Urease GLDH and NADH) and Reagent 2 (tris), Reagent 1 (Picric acid) and Reagent 2 (Sodium hydroxide) were used for Ur and Cr analysis. Reagent A1 (Sodium salicylate, sodium nitroprusside, phosphate buffer) Reagent A2 (Urease) reagent B (Sodium hypochlorite, sodium hydroxide) reagent S (Glucose/Urea/Creatinine standard) used for BUN. Four age groups were studied in our research for both genders. The highest positive coefficient correlation was shown by Ur and BUN with ‘r’=0.99 in this study. The statistical analysis showed a significantly higher average value of Ur, Cr, and BUN in males comparatively than in females with the age group of 61-80 years old. Whereas in the young age group (1-20 years old), female showed a significantly higher value than in the male sex group. Our study revealed a significant variation of Ur, Cr and BUN in male and female with different age groups, as male possessed higher muscle mass with increased dietary protein intakes than females. These biochemical markers aid in the proper assessment and are used for several routine analyses of CKD with different age groups of genders

Seasonal shifts in pronghorn antelope (Antilocapra americana) diets under a new lens: Examining diet composition using a molecular technique.

Foraging is one of the most fundamental activities contributing to the maximization of an animal's fitness, and thus herbivores must optimize their diet selection and intake to meet their nutrient demands for survival, growth, and reproduction. Using plant DNA barcoding, we determined diet composition of five subpopulations of adult female pronghorn antelope (Antilocapra americana) grazing rangelands in southern and southeastern Idaho, USA. Fecal samples were collected for two years (2018-2019), and across metabolically-important adult female life history stages (late gestation, early lactation, breeding season). Plant DNA barcoding yielded 137 detected species within pronghorn diets across subpopulations and sampling periods with forbs being the most abundant. Pronghorn dietary functional group composition ranged from 52.2-60.3% from forbs followed by shrubs (22.6-28.2%), graminoids (8.7-15.7%), and legumes (5.5-9.6%). Dietary protein intake was also highest from forbs and ranged from 32.4-62.4% followed by graminoids (1.2-43.1%), shrubs (18.7-21.3%), and legumes (2.6-7.4%). We found significant intra- and interannual differences in the mean number of genera-based plant detections in pronghorn diets. Dietary protein intake of cultivated legumes (e.g., alfalfa [Medicago sativa] and sainfoin [Onobrychis viciifolia]) was lower than expected, ranging from <1.0-30.8%, suggesting that even within an agricultural-dominated landscape, factors other than plant nutritional composition contributed to pronghorn diets. Although the plant DNA barcoding technique exhibits limitations, it demonstrated potential for elucidating pronghorn dietary species richness, particularly for plants consumed in small proportions, as well as for observing temporal fluctuations in functional group composition and dietary protein intake explained through the interplay between environmental factors, plant chemical composition, and the animals' physiological needs.

Joint Association of Dietary Protein Intake and Eating Habits with the Risk of Gestational Diabetes Mellitus: A Case-Control Study.

Because the associations between different dietary protein sources and the risks of gestational diabetes mellitus (GDM) are inconsistent, and those of eating habits with GDM have rarely been explored, we aimed to investigate the independent and joint association of major dietary protein sources and eating habits with GDM in a case-control study including 353 GDM cases and 718 controls in China. Dietary protein intake and eating habits prior to GDM diagnosis were collected through questionnaires at 24~28 gestational weeks. Multivariate logistic regression was used to evaluate the independent and joint associations of dietary protein intake and eating habits with GDM. The Anderson model was used assess if there is an additive interaction between them. Animal protein, red meat protein and dairy products protein intake were significantly and positively associated with GDM. Among the eating habits, preferences for hot food, firm food and soft food were significantly associated with higher odds of GDM. Individuals with unhealthy eating habits and high dietary protein simultaneously had the highest odds of GDM, and the ORs were 2.06 (1.25, 3.41) for the total protein, 2.97 (1.78, 4.96) for animal meat, 3.98 (2.41, 6.57) for the red meat protein and 2.82 (1.81, 4.41) for the dairy protein; the p values for the trend were all significant (p < 0.001). However, no additive interaction was detected. In conclusion, our study found that dietary protein intake and eating habits prior to GDM diagnosis were both independently and jointly associated with the odds of GDM.

Diet and Other Modifiable Factors in Long-Term Decline of Kidney Function: Observational and Population-Based Cohort Study.

Lower physical activity, lower alcohol intake, higher protein intake, higher sodium intake, and lower potassium intake related to greater kidney function decline over time, according to previous studies. The present study aimed to analyze the cumulative effects of these factors. This prospective, observational, population-based cohort study included 3039 adult examinees of the Gubbio study who participated in the baseline exam and 15-year follow-up exam. Kidney function was evaluated as estimated glomerular filtration rate (eGFR). Habitual physical activity in leisure time and habitual alcohol intake were assessed by questionnaires; dietary intakes of protein, sodium, and potassium were assessed by urinary markers. Based on previous reports, each one of the five modifiable factors was scored 0 for the tertile associated with smaller eGFR decline (low risk), 2 for the tertile associated with greater eGFR decline (high risk), and 1 for the intermediate tertile (intermediate risk). A cumulative score was calculated as the sum of the factor-specific scores and used as the main independent variable. The cumulative score ranged from 0 to 10, that is, from low risk for all factors to high risk for all factors (skewness = 0.032, mean ± SD = 5 ± 2). To avoid the bias of low-n analyses, score 0 was re-coded as 1 and score 10 was recoded as 9; after re-coding, the cumulative score ranged from 1 to 9 (skewness = 0.016, mean ± SD = 5 ± 2). The cumulative score related to annualized eGFR change in multi-variable linear regression (slope = -0.027, 95%CI = -0.039/-0.014, p < 0.001); findings were consistent in apparently healthy examinees and other subgroups. De novo incidence of eGFR < 60 mL/min × 1.73 m2 was higher along the cumulative score (p < 0.001). Compared to score 1 (n examinees = 35, adjusted incidence = 2.0%), incidence of low kidney function was 4.5 times higher in score 5 (n examinees = 624, adjusted incidence = 8.9%) and 6.5 times higher in score 9 (n examinees = 86, adjusted incidence = 12.9%). The cumulative score related to incidence of low kidney function in multi-variable logistic regression (odds ratio = 1.19, 95%CI = 1.08/1.32, p < 0.001). The combination of five modifiable factors predicted large differences in long-term incidence of low kidney function.

Dietary protein recommendations to support healthy muscle ageing in the 21st Century and beyond: considerations and future directions.

This review explores the evolution of dietary protein intake requirements and recommendations, with a focus on skeletal muscle remodelling to support healthy ageing based on presentations at the 2023 Nutrition Society summer conference. In this review, we describe the role of dietary protein for metabolic health and ageing muscle, explain the origins of protein and amino acid (AA) requirements and discuss current recommendations for dietary protein intake, which currently sits at about 0⋅8 g/kg/d. We also critique existing (e.g. nitrogen balance) and contemporary (e.g. indicator AA oxidation) methods to determine protein/AA intake requirements and suggest that existing methods may underestimate requirements, with more contemporary assessments indicating protein recommendations may need to be increased to &gt;1⋅0 g/kg/d. One example of evolution in dietary protein guidance is the transition from protein requirements to recommendations. Hence, we discuss the refinement of protein/AA requirements for skeletal muscle maintenance with advanced age beyond simply the dose (e.g. source, type, quality, timing, pattern, nutrient co-ingestion) and explore the efficacy and sustainability of alternative protein sources beyond animal-based proteins to facilitate skeletal muscle remodelling in older age. We conclude that, whilst a growing body of research has demonstrated that animal-free protein sources can effectively stimulate and support muscle remodelling in a manner that is comparable to animal-based proteins, food systems need to sustainably provide a diversity of both plant and animal source foods, not least for their protein content but other vital nutrients. Finally, we propose some priority research directions for the field of protein nutrition and healthy ageing.

Dietary Potassium and Clinical Outcomes among Patients on Peritoneal Dialysis.

The association between dietary potassium and clinical prognosis is unclear in patients with chronic kidney disease (CKD). Here, we explored the association between dietary potassium intake and all-cause and cardiovascular (CV) mortality in peritoneal dialysis (PD) patients. Here, we present a retrospective analysis of a prospective study. Patients that began incident PD in our center between 1 October 2002 and 31 August 2014 were screened. We recorded all demographic and clinical data at baseline. Repeated measurements were recorded at regular intervals to calculate time-averaged values. Spline regression analysis and Cox proportional regression models were used to evaluate the relationship between dietary potassium and mortality. We followed 881 PD patients for 45.0 (21.5, 80.0) months; 467 patients died, of which 189 (40.5%) died of CV death and 93 were still on PD treatment. Compared with those who had baseline dietary potassium ≥1200 mg/d, the majority of patients with lower dietary potassium were female, older, or poorly educated. They were prone to have poorer nutritional status, CV disease, and diabetes mellitus (p < 0.05). In the unadjusted analysis, both baseline and time-averaged dietary potassium <1200 mg/d predicted higher all-cause and CV mortality (p < 0.001~0.01). After adjusting for demographic and laboratory data, the association between potassium intake and all-cause and CV mortality weakened, which even disappeared after additional adjustment for dietary fiber, protein, and energy intake. Dietary potassium in PD patients was not independently associated with all-cause and CV mortality.

Dietary protein restriction modulates ‘dessert’ intake after a meal, via fibroblast growth factor 21 (FGF21)

Pharmacological administration of fibroblast growth factor 21 (FGF21) alters food choice, including that it decreases the consumption of sucrose and other sweet tastants. Conversely, endogenous secretion of FGF21 by the liver is modulated by diet, such that plasma FGF21 is increased after eating foods that have a low dietary protein: total energy (P: E) ratio. Together, these findings suggest a strategy to promote healthy eating, in which the macronutrient content of a pre-load diet could reduce the consumption of sweet desserts in sated mice. Here, we tested the prediction that individuals maintained on a low P: E diet, and offered a highly palatable sweet ‘dessert’ following a pre-load meal, would eat less of the sugary snack compared to controls—due to increased FGF21 signaling. In addition to decreasing sweet intake, FGF21 increases the consumption of dietary protein. Thus, we predicted that individuals maintained on the low P: E diet, and offered a very high-protein pellet as ‘dessert’ or snack after a meal, would eat more of the high protein pellet compared to controls, and that this depends on FGF21. We tested this in C57Bl/6J, and liver-specific FGF21-null (FGF21ΔL) null male and female mice and littermate controls. Contrary to expectation, eating a low protein pre-load did not reduce the later consumption of a sweet solution in either males or females, despite robustly increasing plasma FGF21. Rather, eating the low protein pre-load increased later consumption of a high protein pellet. This was more apparent among males and was abrogated in the FGF21ΔL mice. We conclude that physiologic induction of hepatic FGF21 by a low protein pre-load diet is not sufficient to reduce the consumption of sweet desserts, though it effectively increases the subsequent intake of dietary protein in male mice.

Validation of a food frequency questionnaire in the assessment of dietary glycemic index, glycemic load, and protein intake in pregnant women with obesity

ObjectivesStudies suggest that diets with a low glycemic index and high protein are favorable in aiding weight loss and improving weight maintenance; however, methods to measure dietary intake are comprehensive both for the participant and the study staff. We aimed to validate the accuracy of the dietary glycemic index and protein intake assessed through a food frequency questionnaire against a 4-d weighed food record in Danish pregnant women with obesity. MethodsA total of 31 pregnant women completed a 29-item food frequency questionnaire and a 4-d weighed food record with overlapping time periods. The women had a mean (± SD) age of 30.6 ± 3.9 y and a prepregnancy body mass index of 33.9 ± 3.5 kg/m2. We evaluated the validity of the food frequency questionnaire by Bland-Altman plots and the Spearman correlation coefficient. ResultsThe results of the validation study found good acceptance of the 29-item food frequency questionnaire. The mean intake of glycemic index, glycemic load, and protein intake of the 29-item food frequency questionnaire and the weighed food record correlated well, although intake data of the 29-item food frequency questionnaire tended to be lower. Spearman correlation coefficients had moderate to high correlations for glycemic index (ρ = 0.73; P < 0.001) and protein intake (ρ = 0.70; P < 0.001). A moderate correlation was found for glycemic load (ρ = 0.55; P = 0.002). There was no correlation for carbohydrates (ρ = 0.21; P = 0.253). ConclusionThe results suggest no risk of bias between the two methods of assessment; hence, a 29-item food frequency questionnaire can be used to assess the mean glycemic index, glycemic load, and protein intake in pregnant women with obesity.

Evidence for the protein leverage hypothesis in preschool children prone to obesity

The protein leverage hypothesis (PLH) proposed that strict regulation of protein intake drives energy overconsumption and obesity when diets are diluted by fat and/or carbohydrates. Evidence about the PLH has been found in adults, while studies in children are limited. Thus, we aimed to test the PLH by assessing the role of dietary protein on macronutrients, energy intake, and obesity risk using data from preschool children followed for 1.3 years. 553 preschool children aged 2-6 years from the 'Healthy Start' project were included. The proportion of energy intake from protein, fat, and carbohydrates collected from a 4-day dietary record. Energy intake, BMI z-score, fat mass (FM) %, waist- (WHtR) and hip-height ratio (HHtR). Power function analysis was used to test the leverage of protein on energy intake. Mixture models were used to explore interactive associations of macronutrient composition on all these outcomes, with results visualized as response surfaces on the nutritional geometry. Evidence for the PLH was confirmed in preschool children. The distribution of protein intake (% of MJ, IQR: 3.2) varied substantially less than for carbohydrate (IQR: 5.7) or fat (IQR: 6.3) intakes, suggesting protein intake is most tightly regulated. Absolute energy intake varied inversely with dietary percentage energy from protein (L=-0.14, 95% CI:-0.25,-0.04). Compared to children with high fat or carbohydrate intakes, children with high dietary protein intake (>20% of MJ) had a greater decrease in WHtR and HHtR over the 1.3-year follow-up, offering evidence for the PLH in prospective analysis. But no association was observed between macronutrient distribution and changes in BMI z-score or FM%. In this study in preschool children, protein intake was the most tightly regulated macronutrient, and energy intake was an inverse function of dietary protein concentration, indicating the evidence for protein leverage. Increases in WHtR and HHtR were principally associated with the dietary protein dilution, supporting the PLH. These findings highlight the importance of protein in children's diets, which seems to have significant implications for childhood obesity risk and overall health.

DNA Methylation at ABCG1 and Long-term Changes in Adiposity and Fat Distribution in Response to Dietary Interventions: The POUNDS Lost Trial.

To examine whether participants with different levels of diabetes-related DNA methylation at ABCG1 might respond differently to dietary weight loss interventions with long-term changes in adiposity and body fat distribution. The current study included overweight/obese participants from the POUNDS Lost trial. Blood levels of regional DNA methylation at ABCG1 were profiled by high-resolution methylC-capture sequencing at baseline among 673 participants, of whom 598 were followed up at 6 months and 543 at 2 years. Two-year changes in adiposity and computed tomography-measured body fat distribution were calculated. Regional DNA methylation at ABCG1 showed significantly different associations with long-term changes in body weight and waist circumference at 6 months and 2 years in dietary interventions varying in protein intake (interaction P < 0.05 for all). Among participants assigned to an average-protein (15%) diet, lower baseline regional DNA methylation at ABCG1 was associated with greater reductions in body weight and waist circumference at 6 months and 2 years, whereas opposite associations were found among those assigned to a high-protein (25%) diet. Similar interaction patterns were also observed for body fat distribution, including visceral adipose tissue, subcutaneous adipose tissue, deep subcutaneous adipose tissue, and total adipose tissue at 6 months and 2 years (interaction P < 0.05 for all). Baseline DNA methylation at ABCG1 interacted with dietary protein intake on long-term decreases in adiposity and body fat distribution. Participants with lower methylation at ABCG1 benefitted more in long-term reductions in body weight, waist circumference, and body fat distribution when consuming an average-protein diet.

Association of Frailty With Nutritional Status in Patients With Chronic Kidney Disease

Frailty is commonly observed in patients with chronic kidney disease (CKD) and is associated with adverse outcomes. Protein-energy wasting (PEW), a state of decreased body stores of protein and energy fuels, may be associated with frailty. However, few data are available on the possible association between frailty and PEW in CKD. We examined the association between frailty and nutritional status assessed using anthropometric and body composition measurements, serum albumin, handgrip strength, the Malnutrition Inflammation Score (MIS), and dietary protein and calorie intake in a cross-sectional analysis of nondialysis patients with CKD stages 3-5. Body composition was assessed using multifrequency bioelectrical impedance. Frailty was defined as a Clinical Frailty Scale ≥4. We performed logistic regression with different nutrition assessment tools as the main predictors and age, sex, comorbidity, estimated glomerular filtration rate (eGFR), and hemoglobin as covariates. A total of 157 patients (93 men and 64 women; mean age 64years; diabetes prevalence 38.9%) with CKD (eGFR 24.4±13.4mL/min/1.73m2) were included. Overall, 29.3% of patients were frail. Patients with frailty were older and had a significantly higher fat tissue index and MIS but a significantly lower lean tissue index, eGFR, hemoglobin value, serum albumin value, handgrip strength value, and dietary protein intake. In multivariate logistic regression analyses, a higher body mass index category (odds ratio [OR], 1.54; 95% confidence interval [CI], 1.03-2.31), higher fat tissue index (OR, 1.15; 95% CI, 1.03-1.28), larger waist circumference (OR, 1.05; 95% CI, 1.01-1.09), reduced handgrip strength (OR, 2.70; 95% CI, 1.17-6.21), PEW defined by MIS ≥5 (OR, 3.49; 95% CI, 1.35-9.01), and dietary protein intake ≤0.8g/kg/day (OR, 2.70; 95% CI, 1.18-6.19) were associated with higher odds of frailty. Frailty is associated with nutritional status in patients with CKD. A comprehensive nutrition assessment may allow the implementation of strategies to prevent or reduce frailty.

Mapping the global research landscape on malnutrition for patients with chronic kidney disease: a visualization analysis

BackgroundChronic kidney disease (CKD) is seen as a diverse disease and a primary contributor to global mortality. Malnutrition arises within chronic illness, which involves protein energy depletion and inadequate levels of essential nutrients. These factors increase the likelihood of death and the overall impact of the disease on affected individuals. Consequently, this study aims to utilize bibliometric and visual analysis to assess the current state of research, the latest advances and emerging patterns in the fields of CKD and malnutrition.MethodsExtensive research was conducted using the Scopus database, which is the most authoritative database of research publications and citations, to focus on CKD research between 2003 and 2022, as indicated by title and author keywords. Then, within this vast collection of academic publications, a notable subset of articles was exclusively dedicated to investigating the relationship between CKD and malnutrition. Finally, we performed bibliometric analysis and visualization using VOSviewer 1.6.19 and Microsoft Excel 2013.ResultsLarge global research between 2003 and 2022 resulted in 50,588 documents focused on CKD, as indicated by title and author keywords. In this extensive collection of scientific publications, a staggering portion of 823 articles is devoted exclusively to investigating the link between CKD and malnutrition. Further analysis reveals that this body of work consists of 565 articles (68.65%), 221 reviews (26.85%), and 37 miscellaneous entries (4.50%), which encompass letters and editorials. The USA was found to be the most productive country (n = 173; 21.02%), followed by Italy (n = 83; 10.09%), Sweden (n = 56; 6.80%), Brazil (n = 54; 6.56%) and China (n = 51; 6.20%). The most common terms on the map include those related to the topic of (a) malnutrition in hemodialysis patients and predicting factors; terms associated with the (b) impact of malnutrition on cardiovascular risk and complications in CKD patients; and terms related to the (c) dietary protein intake and malnutrition in CKD.ConclusionsThis study is the first of its kind to analyze CKD and malnutrition research using data from Scopus for visualization and network mapping. Recent trends indicate an increasing focus on protein-energy wasting/malnutrition in hemodialysis patients and predicting factors, dietary protein intake, and malnutrition in CKD. These topics have gained significant attention and reflect the latest scientific advances. Intervention studies are crucial to examining diet therapy's impact on patients with stages 1 to 5 CKD. We hope this study will offer researchers, dietitians and nephrologists valuable information.

Effects of correcting metabolic acidosis on muscle mass and functionality in chronic kidney disease: a systematic review and meta-analysis.

Metabolic acidosis unfavourably influences the nutritional status of patients with non-dialysis dependent chronic kidney disease (CKD) including the loss of muscle mass and functionality, but the benefits of correction are uncertain. We investigated the effects of correcting metabolic acidosis on nutritional status in patients with CKD in a systematic review and meta-analysis. A search was conducted in MEDLINE and the Cochrane Library from inception to June 2023. Study selection, bias assessment, and data extraction were independently performed by two reviewers. The Cochrane risk of bias tool was used to assess the quality of individual studies. We applied random effects meta-analysis to obtain pooled standardized mean difference (SMD) and 95% confidence intervals (CIs). We retrieved data from 12 intervention studies including 1995 patients, with a mean age of 63.7±11.7years, a mean estimated glomerular filtration rate of 29.8±8.8mL/min per 1.73m2 , and 58% were male. Eleven studies performed an intervention with oral sodium bicarbonate compared with either placebo or with standard care and one study compared veverimer, an oral HCl-binding polymer, with placebo. The mean change in serum bicarbonate was +3.6mEq/L in the intervention group and +0.4mEq/L in the control group. Correcting metabolic acidosis significantly improved muscle mass assessed by mid-arm muscle circumference (SMD 0.35 [95% CI 0.16 to 0.54], P<0.001) and functionality assessed with the sit-to-stand test (SMD -0.31 [95% CI -0.52 to 0.11], P=0.003). We found no statistically significant effects on dietary protein intake, handgrip strength, serum albumin and prealbumin concentrations, and blood urea nitrogen. Correcting metabolic acidosis in patients with CKD improves muscle mass and physical function. Correction of metabolic acidosis should be considered as part of the nutritional care for patients with CKD.