Protein Intake and Human Health: Implications of Units of Protein Intake

Development and Kohonen neural network based cluster analysis of red rice cookies enriched with blends of different edible seeds flour

This study aimed to prepare cookies using red rice flour (RRF) and edible seed flour (ESF) and analyze their nutritional and physical characteristics using exploratory methods. Effect of blended mixtures were investigated with varying levels of ESF to RRF in mass incremental ratios of 0 %:100 %, 25 %:75 %, 50 %:50 %, 75 %:25 % and 100 %:0 %. According to one-way analysis of variance (ANOVA), fortified cookies contained significantly higher levels (p < 0.05) of protein, fibers; with reduced fat content and spread-ratio. Results were analyzed using Kohonen's Self-Organizing Maps (KSOMs), which grouped samples based on similar nutritional and physical properties. Analysis yielded desirable Davies-Bouldin (0.14-0.30) and Silhouette indices (0.97-0.98), indicating well-separated clusters with minimal overlap. Cookies blend containing 25 % ESF+ 75 % RRF exhibited higher sensory attributes, minerals, amino-acids and antioxidants compared to control cookies, hence demonstrating ESF and RRF as promising functional ingredients to improve nutritional quality.

Association between animal protein intake and overweight/obesity: A systematic review and meta-analysis of observational studies

AIMS

To conduct a systematic review and meta-analysis of observational studies to investigate the association between Animal Protein Intake (API) and overweight/obesity across different age groups.

DATA SYNTHESIS

This review is registered in the International Prospective Register Of Systematic Reviews - PROSPERO database (CRD42023467451). Observational studies on the association between API and the outcome of overweight/obesity were included, up to September 2024, from ten databases. The risk of bias and study quality appraisal was assessed using the Agency for Health Care Research and Quality (AHRQ) tools for cross-sectional studies and the Newcastle-Ottawa Scale (NOS) for cohort studies. A systematic review and meta-analysis were performed with 14 and 11 studies, respectively, assessing individuals aged eight to 89 years, 55 % female. The meta-analysis indicated an increased likelihood of obesity with API in two cross-sectional studies (OR 1.18; 95 %CI 1.12-1.24; p < 0.001; I2: 0 %). Daily intake of animal protein ranging from 44.7 to 67.8 g/day (or 8.8 %-11.4 % of Kcal/day, on average) was associated with obesity. The risk of bias was considered low/moderate for most studies according to AHRQ, and four of the six cohort studies were rated as moderate quality by NOS.

CONCLUSIONS

API appears to be associated with a higher likelihood of developing overweight/obesity, and increased Body Mass Index (BMI). Despite the multicausal nature of obesity, these findings suggest that reducing API may decrease the likelihood of overweight/obesity in the studied age groups.

Postprandial Aminoacidemia Following the Ingestion of Alternative and Sustainable Proteins in Humans: A Narrative Review

There is a pressing need to expand the production and consumption of alternative protein sources from plants, fungi, insects, and algae from both nutritional and sustainability perspectives. It is well known that the postprandial rise in plasma amino acid concentrations and subsequent muscle anabolic response is greater after the ingestion of animal-derived protein sources, such as dairy, meat, and eggs, than plant-based proteins. However, emerging evidence shows that a similar muscle anabolic response is observed-despite a lower and slower postprandial aminoacidemia-after the ingestion of alternative protein sources compared with animal-derived protein sources. Therefore, a comprehensive analysis of plasma amino acid kinetics after the ingestion of alternative protein sources would play a significant role in recognizing and identifying the anabolic properties of these protein sources, allowing for the implementation of the best nutritional intervention strategies, contributing to more sustainable food production, and developing new medical nutritional products with optimal impacts on muscle mass, strength, and function, both in terms of health and disease. Therefore, this narrative review is focused on postprandial amino acid kinetics (the area under the curve, peak, and time to reach the peak concentration of amino acids) based on experimental randomized controlled trials performed in young and older adults following the ingestion of different novel, sustainable, and alternative protein sources.

Association between protein intake, diet quality, and obesity in Australian adults: a comparison of measurement units

Previous investigations on protein associations with diet quality and obesity still have inconclusive findings, possibly due to how protein intake was expressed. This study aimed to compare how different ways of expressing total protein intake may influence its relationships with diet quality and obesity. Usual protein intake was estimated from the 2011-12 Australian National Nutrition and Physical Activity Survey (n = 7637 adults, ≥19 years), expressed in grams (g/d), percent energy (%EI), and grams per actual kilogram body weight (g/kgBW/d). Diet quality was assessed using the 2013 Dietary Guidelines Index, and obesity measures included Body Mass Index (BMI) and waist circumference (WC). Sex-stratified multiple linear and logistic regressions were performed and adjusted for potential confounders. Total protein (g/d) was directly associated with diet quality (males, β = 0.15 (95% CI 0.12, 0.19); females, β = 0.25 (0.22, 0.29)), and this association was consistent across units. Protein intake (g/d) was directly associated with BMI (males, β = 0.07% (0.04%, 0.11%); females, β = 0.09% (0.04%, 0.15%)), and WC (males, β = 0.04 (0.01, 0.06); females, β = 0.05 (0.00, 0.09)). While in males, protein as %EI was associated with higher WC, no association was found in females. Adults with higher protein intake (g/d) had higher odds of overweight/obesity (males, OR = 1.01 (1.00, 1.01); females, OR = 1.01 (1.00, 1.01)), and central overweight/obesity (females, OR = 1.01 (1.00, 1.01)), but no significant association with females odds of overweight/obesity when protein was expressed in %EI. In conclusion, protein intake was positively associated with diet quality and obesity, yet these associations were stronger for women. The effect sizes also varied by measurement unit due to the different scales of those units.

Sex-Specific Variation in Metabolic Responses to Diet

Suboptimal nutrition is a leading cause of cardiometabolic disease and mortality. Biological sex is a variable that influences individual responses to dietary components and may modulate the impact of diet on metabolic health and disease risk. This review describes findings of studies reporting how biological sex may associate with or affect metabolic outcomes or disease risk in response to varying dietary macronutrient content, Mediterranean diet, Western diet, and medical very low-calorie diet. Although few dietary interventions have been specifically designed to identify sex-diet interactions, future studies improving understanding how sex influences dietary responses could inform precision nutrition interventions for disease prevention and management.

Distribution of daily protein intake and appendicular skeletal muscle mass in healthy free-living Chinese older adults

AIMS

Evidence regarding impact of protein intake distribution on skeletal muscle mass in older adults is limited and inconsistent. This study aims to investigate the relationship of evenness of dietary protein distribution and number of meals exceeding a threshold with appendicular skeletal muscle mass (ASM) in healthy and free-living Chinese older adults.

METHODS

Repeated measured data of 5689 adult participants aged ≥ 60 years from the China Health and Nutrition Survey (CHNS) 2015 and 2018 waves were analyzed. Mixed-effects linear regression model was performed to examine the relationship between coefficient of variance (CV) of protein intake across meals, number of meals ≥ 0.4 g protein/kg BW and ASM, respectively. Analyses were conducted separately for male and female.

RESULTS

The average CV of protein intake in each wave was in the range of 0.34-0.35. More than 40% male and female participants in each wave had no meal reaching 0.4 g protein/kg BW. Female participants in the highest quartile of protein intake CV had significantly lower ASM (β = -0.18, 95%CI = -0.32, -0.04) compared with those in the lowest quartile, after adjustment for multiple confounders. Significant negative trends were observed across dietary protein CV quartiles with ASM both in male (P trend = 0.043) and female (P trend = 0.007). Significant positive association between number of meals exceeding 0.4 g protein /kg BW and relative ASM were observed in females (2 meals vs. 0 meal: β = 0.003, 95%CI = 0.0007,0.006;≥3 meals vs. 0 meal: β = 0.008, 95%CI = 0.003,0.013), after adjusting for multiple covariates.

CONCLUSIONS

A more even-distributed protein intake pattern and more meals reaching protein intake threshold were respectively associated with higher appendicular skeletal muscle mass in healthy and free-living older Chinese adults. Prospective studies and intervention trials are needed to confirm these cross-sectional findings.

Associations between Essential Amino Acid Intake and Functional Health Outcomes in Older Adults: Analysis of the National Health and Nutrition Examination Survey, 2001-2018

Background

The relationships between habitual essential amino acid (EAA) intake and body composition, muscle strength, and physical function in older US adults are not well defined.

Objectives

This cross-sectional study evaluated associations between usual EAA intakes and body composition, muscle strength, and physical function in US adults ≥65 y.

Methods

The Food and Nutrient Database for Dietary Studies (FNDDS) 2001-2018 was linked to the US Department of Agriculture Standard Reference database to access existing amino acid composition data for FNDDS ingredients. FNDDS ingredients without existing amino acid composition data were matched to similar ingredient codes with available data. Usual EAA, leucine, lysine, and sulfur-containing amino acid (SAA; methionine + cysteine) intakes (g/d) from National Health and Nutrition Examination Survey 2001-2018 were calculated for individuals ≥65 y (n = 10,843). Dependent variables included muscle strength measured by isometric grip test, body mass index (BMI), waist circumference, dual-energy X-ray absorptiometry-measured appendicular lean mass and whole-body fat mass, and self-reported physical function (that is, tasks of daily living). Regression analyses were used to determine covariate-adjusted relationships between EAA, leucine, lysine, and SAA intake and functional health outcomes. P < 0.0013 was considered significant.

Results

EAA, leucine, lysine, and SAA intakes, covaried with physical activity level and usual protein intake, were not associated with muscle strength or self-reported physical function in males or females or with body composition in males. EAA intakes were positively associated with waist circumference in females (β ± SEM, 2.1 ± 0.6 cm, P = 0.0007). Lysine intakes were positively associated with BMI (3.0 ± 0.7 kg/m2, P < 0.0001) and waist circumference (7.0 ± 1.7 cm, P = 0.0001) in females.

Conclusions

Habitual EAA, leucine, lysine, and SAA intakes, covaried with physical activity level and usual protein intake, were not associated with lean mass, muscle strength, or physical function in adults ≥65 y. However, EAA intakes, particularly lysine, were positively associated with measures of adiposity in older females.This trial was registered with the Open Science Framework (https://doi.org/10.17605/OSF.IO/25V63) as osf.io/25v63).

Analysis of the Association between Protein Intake and Disability-Adjusted Life Year Rates for Alzheimer's Disease in Japanese Aged over 60

With advancements in medical technology, the structure of disease is shifting from acute illnesses to chronic conditions, such as Alzheimer's disease (AD). Consequently, there is an escalating need for evaluations that discourse on the potential effects on healthy life years, as well as disease onset. We aimed to evaluate the associations with AD disability-adjusted life year (AD-DALY) rates and protein intake by sex and age group. For the analysis, we used representative values for males and females in their 60s and aged over 70, extracted from the public dataset of the Global Burden of Disease Study and the National Health and Nutrition Survey in Japan, covering the years 1990 to 2019. In order to evaluate the association between AD-DALY rates and protein intake, we analyzed correlations and stratified multiple regression models. Additionally, we simulated alterations in AD-DALY rates associated with changes in protein intake by utilizing stratified multiple regression models. AD-DALY rates and protein intake indicated significant negative correlations across all sex and age groups. In stratified multiple regression models, significant associations were found between higher protein intake and lower AD-DALY rates in females. In the simulation, when protein intake was increased to 1.5 g/kg/day, AD-DALY rates decreased by 5-9 percent compared with 2019. However, the association between intake of animal and plant protein and AD-DALY rates were found to vary based on sex and age group. The present study suggests the possibility to improve AD-DALY rates by increasing population average protein intake levels in a recommended range.

Protein intake and body weight, fat mass and waist circumference: an umbrella review of systematic reviews for the evidence-based guideline on protein intake of the German Nutrition Society

PURPOSE

This umbrella review aimed to assess whether dietary protein intake with regard to quantitative (higher vs. lower dietary protein intake) and qualitative considerations (total, plant-based or animal-based protein intake) affects body weight (BW), fat mass (FM) and waist circumference (WC).

METHODS

A systematic literature search was conducted in PubMed, Embase and Cochrane Database of Systematic Reviews for systematic reviews (SRs) with and without meta-analyses of prospective studies published between 04 October 2007 and 04 January 2022. Methodological quality and outcome-specific certainty of evidence of the retrieved SRs were assessed by using AMSTAR 2 and NutriGrade, respectively, in order to rate the overall certainty of evidence using predefined criteria.

RESULTS

Thirty-three SRs were included in this umbrella review; 29 were based on randomised controlled trials, a few included cohort studies. In studies without energy restriction, a high-protein diet did not modulate BW, FM and WC in adults in general (all "possible" evidence); for older adults, overall certainty of evidence was "insufficient" for all parameters. Under hypoenergetic diets, a high-protein diet mostly decreased BW and FM, but evidence was "insufficient" due to low methodological quality. Evidence regarding an influence of the protein type on BW, FM and WC was "insufficient".

CONCLUSION

"Possible" evidence exists that the amount of protein does not affect BW, FM and WC in adults under isoenergetic conditions. Its impact on the reduction in BW and FM under hypoenergetic conditions remains unclear; evidence for an influence of protein type on BW, FM and WC is "insufficient".

Effect of dietary protein intake on cognitive function in the elderly with chronic kidney disease: analysis of the National Health and Nutrition Examination Survey 2011-2014

BACKGROUND

Cognitive dysfunction is prevalent among the elderly diagnosed with chronic kidney disease (CKD). Low protein diets are used for retarding the progression of CKD in clinical practice. Nonetheless, the impact of dietary protein consumption on cognitive function in this population remains uncertain.

METHODS

We recruited 2306 participants (≥60 years) from 2011 to 2014 National Health and Nutrition Examination Survey (NHANES). 24-h dietary recall questionnaire was utilized to evaluate protein intake. Cognitive function was measured using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST). Participants' characteristics were analyzed, and the interaction between protein consumption and CKD on cognitive impairment were analyzed using a logistic regression model.

RESULTS

We divided participants into three groups based on CKD stages: no CKD, CKD stage G1 to G2 (19%), and CKD stage G3 to G5 (18%). The average protein intake was 0.97 g/(kg·d). In the higher protein intake group, CKD stages G1 to G2 elevated the risk of immediate memory impairment (OR: 2.441, 95% Cl: 1.161-5.132 for protein consumption in 1.0-1.2g/(kg·d); OR: 2.225, 95% Cl: 1.015-4.876 for protein consumption in >1.2 g/(kg·d)). However, no similar resuts were observed in the lower protein intake group. In addition, the interaction between CKD status and protein intake on immediate memory was statistically significant (p = .041).

CONCLUSION

A higher probability of cognitive impairment in the elderly with early-stage CKD may be linked to higher protein intake. Low protein diets may be a potential strategy to release cognitive impairment in the elderly with early-stage CKD.

Association of protein intake with recurrence and survival following primary treatment of ovarian cancer

BACKGROUND

Malnutrition is common during treatment for ovarian cancer and one in three report multiple symptoms affecting food intake after primary treatment. Little is known about diet post-treatment in relation to ovarian cancer survival, however, general recommendations for cancer survivors are to maintain a higher level of protein intake to support recovery and minimize nutritional deficits.

OBJECTIVE

To investigate whether intake of protein and protein food sources following primary treatment for ovarian cancer is associated with recurrence and survival.

DESIGN

Intake levels of protein and protein food groups were calculated from dietary data collected about 12 months post-diagnosis using a validated food frequency questionnaire in an Australian cohort of females with invasive epithelial ovarian cancer. Disease recurrence and survival status were abstracted from medical records (median 4.9 years follow-up). Cox proportional hazards regression was used to calculate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for protein intake and progression-free and overall survival.

RESULTS

Among 591 females who were progression-free at 12-months follow-up, 329 (56%) subsequently experienced cancer recurrence and 231 (39%) died. A higher level of protein intake was associated with better progression-free survival (>1-1.5 vs. ≤1 grams per kilogram body weight (g/kg): HR_adjusted=0.69, 95% CI 0.48, 1.00; >1.5 vs. ≤1g/kg: HR_adjusted=0.61, 95% CI 0.41, 0.90; >20% vs. ≤20% total energy intake from protein: HR_adjusted=0.77, 95% CI 0.61, 0.96). There was no evidence for better progression-free survival with any particular protein food sources. There was a suggestion of better overall survival among those with higher total intakes of animal-based protein foods, particularly dairy products (HR=0.71, 95% CI 0.51, 0.99 for highest vs. lowest tertiles of total dairy intake).

CONCLUSIONS

After primary treatment for ovarian cancer, a higher level of protein intake may benefit progression-free survival. Ovarian cancer survivors should avoid dietary practices that limit intake of protein-rich foods.

Amino Acid Intake and Conformance With the Dietary Reference Intakes in the United States: Analysis of the National Health and Nutrition Examination Survey, 2001-2018

BACKGROUND

The lack of complete amino acid composition data in food composition databases has made determining population-wide amino acid intake difficult.

OBJECTIVES

This cross-sectional study characterizes habitual intakes of each amino acid and adherence to dietary requirements for each essential amino acid (EAA) in the US population.

METHODS

Food and Nutrient Database for Dietary Studies ingredient codes with missing amino acid composition data were matched to similar ingredients with available data so that amino acid composition could be determined for 100% of foods reported in the dietary intake assessment component of NHANES. Amino acid intakes during NHANES 2001-2018 (n = 72,831; ≥2 y) were calculated as relative (mg·kg of ideal body weight^-1·d^-1) intakes. Data from NHANES 2011-2018 were used to determine the percentage of population consuming less than that recommended by the DRIs for each EAA by age, sex, and race/ethnicity.

RESULTS

Relative intakes of EAAs and NEAAs were greatest in those 2-3 y and lowest in older individuals (≥71 y or ≥80 y). In females aged 2-18 y, relative intakes of EAAs were lowest in non-Hispanic White (NHW; histidine, lysine, threonine, methionine, and cysteine) and non-Hispanic Black (NHB; valine, isoleucine, leucine, phenylalanine, tryptophan, and tyrosine) populations and highest in the Asian population. In females aged ≥19 y, relative intakes were lowest in NHW (lysine and methionine only) and NHB populations and highest in the Asian population. In males aged 2-18 y, relative intakes of EAAs were lowest in the NHB population and highest in the Asian population. In males ≥19 y, relative intakes were lowest in NHB and NHW (lysine only) populations and highest in the Hispanic population. Less than 1% of individuals aged ≥19 y did not meet the Estimated Average Requirements for each EAA.

CONCLUSIONS

EAA intakes in the US population exceed recommended minimum population requirements. Future studies can use the method described here to quantify amino acid intake and examine relationships with health and disease.

Influence of Soil Nutrient Toxicity and Deficiency from Three Ecuadorian Climatic Regions on the Variation of Biological, Metabolic, and Nutritional Properties of Moringa oleifera Lam

Moringa oleifera Lam. contains numerous essential constituents found in all plant parts (leaves, pods, and seeds). From all its edible parts, the leaf represents an effective remedy with high potential for medicinal applications. Ecuador is part of the new promising cultivation areas for Moringa, and therefore our study is emphasized to determine the influence of soil nutrition, toxicity (excess), and deficiency, from three main areas of this country, correlated with its climatic characteristics, on the mineral components, bioactive compounds' synthesis, and antioxidant capacity of Moringa. Different analyses were performed in soil and especially leaf samples for phytochemical content, antioxidant activity, calcium, protein, and vitamin C determination to identify the relationship between soil nutrients, abiotic conditions, and the therapeutic potential of this species cultivated in Ecuador. The obtained values using methods such as DPPH, FRAP, and ABTS showed a high antioxidant capacity of the leaves from the Coastal Ecuadorian region, related with total phenolic compounds' content (through the Folin-Ciocalteu method) and flavonoids in samples, with results obtained under the positive influence of high soil nutrients such as Ca, Mg, Mn, and Fe. We can conclude that M. oleifera from the coastal area of Ecuador presents the right environmental and soil conditions to positively influence its mineral and phytochemical content, making it suitable for incorporation into foods and medicines to solve the nutritional and medical problems in Ecuador and worldwide.