The Link between Dietary Protein Intake, Skeletal Muscle Function and Health in Older Adults

Enhanced Nutritional and Functional Recovery in Femur Fracture Patients Post-Surgery: Preliminary Evidence of Muscle-Targeted Nutritional Support in Real-World Practice

Background/Objectives: To describe the effects of muscle-targeted oral nutritional supplementation (MT-ONS) on nutrition, functional capacity, and other health outcomes in patients after femur fracture surgery. Methods: A prospective, open-label, single-centre study was conducted. Patients aged 80+ post-femur fracture were recruited. They were assessed at baseline and after 90 days with MT-ONS, 100% whey protein enriched with leucine and vitamin D. Demographics, clinical and nutritional status (MNA®-SF), functional capacity [Barthel Index (BI), Lawton and Brody (LB) scale], muscle strength (dynamometry), cognition [Global Deterioration Scale (GDS)], tolerability, and satisfaction data were collected. Descriptive statistics were performed. Ethical approval was obtained. Results: Thirty-one patients (74% women, mean age 87 ± 3.99 years) were enrolled. At baseline, 32% were malnourished and 65% were at risk. After ≥90 days of MT-ONS, malnutrition decreased to 13% and well-nourishment increased to 32%. Ninety percent gained weight, with significant muscle strength improvements (+2 kg, p < 0.001). Eighty-one percent achieved a BI score ≥ 60 points [mean 84.8 (±17.82)]. BI score improvements correlated with higher baseline muscle strength (rho = 0.413, p = 0.021) and better nutritional status (rho = 0.464, p = 0.009). The mean LB score was 4.84 (±2.26). Improvements correlated with the pre-fracture BI score (rho = 0.475, p = 0.007). Positive correlations were noted between nutritional status, muscle strength, and functional outcomes. Cognition remained stable (GDS = 1 in 67.7% patients). Tolerability and satisfaction with MT-ONS were high at 90%. Conclusions: MT-ONS, 100% whey protein enriched with leucine and vitamin D, for ≥90 days enhances nutritional status and functional recovery in patients after femur fracture surgery.

The Potential of Dehydrated Geniotrigona thoracica Stingless Bee Honey against Metabolic Syndrome in Rats Induced by a High-Carbohydrate, High-Fat Diet

BACKGROUND/OBJECTIVES

Metabolic syndrome (MS) is diagnosed when at least three out of five key risk factors are present: obesity, high blood pressure, insulin resistance, high triglycerides (TG) and low high-density lipoprotein (HDL). MS is often associated with chronic low-grade inflammation. Recent studies have shown that raw stingless bee honey (SBH) can alleviate MS risk factors. However, the high moisture content in raw SBH predisposes it to fermentation, which can degrade its quality. Therefore, dehydrating SBH is necessary to prevent the fermentation process. This study aimed to compare the effects of dehydrated (DeGT) and raw (RGT) SBH from Geniotrigona thoracica species on high-carbohydrate, high-fat diet (HCHF)-induced MS in rats.

METHODS

Twenty-four male Wistar rats were divided into four groups: control (C), HCHF-induced MS without treatment (MS), HCHF-induced MS treated with DeGT (MS+DeGT) and HCHF-induced MS treated with RGT (MS+RGT). Group C received standard rat chow, while the other groups were fed with HCHF diet for 16 weeks. In the final eight weeks, two HCHF-induced groups received their respective SBH treatments.

RESULTS

Both DeGT and RGT treatments reduced energy intake, fat mass, high blood pressure, inflammatory (tumour necrosis factor-alpha (TNF-α)) and obesity (the leptin/adiponectin (L/A) ratio, corticosterone, 11 beta-hydroxysteroid dehydrogenase type-1 (11βHSD1)) markers, as well as prevented histomorphometry changes (prevented adipocyte hypertrophy, increased the Bowman's space area and glomerular atrophy). Additionally, DeGT increased serum HDL levels, while RGT reduced serum TG, leptin and other inflammatory markers (interleukin-6 (IL-6) and interleukin-1 beta (IL-1β)), as well as hepatosteatosis.

CONCLUSIONS

While DeGT demonstrates potential as a preventive agent for MS, RGT exhibited more pronounced anti-MS effects in this study.

Large Discordance between Creatinine-Based and Cystatin C-Based eGFRs is Associated with Falls, Hospitalizations, and Death in Older Adults

Key Points

A large eGFR discordance (i.e ., cystatin C–based eGFR >30% lower than creatinine-based eGFR) is common in older adults and increased with age. A large eGFR discordance was associated with increased risk of falls, hospitalization, and death, independent of kidney function. There are multiple ways to measure differences in creatinine and cystatin C; all produce similar associations with aging-related adverse outcomes.

Background

eGFR calculated using creatinine and cystatin C often differ in older adults. We hypothesized that older adults with cystatin C–based eGFR (eGFRcys) values significantly lower than creatinine-based eGFR (eGFRcr) values may have higher risk of aging-related adverse outcomes, independent of kidney function.

Methods

We conducted a longitudinal cohort study of adults 65 years and older from the Health and Retirement Study, a cohort of older American adults, to determine the relationship between eGFR discordance and aging-related adverse outcomes. We calculated eGFRcr and eGFRcys using baseline creatinine and cystatin C measurements. A large eGFR discordance was defined as eGFRcys >30% lower than eGFRcr. We assessed four aging-related adverse outcomes over a 2-year follow-up: falls, hip fractures, hospitalizations, and death. We fit separate multivariable regression models to determine the association between having a large eGFR discordance and each outcome adjusting for confounders, including kidney function.

Results

Of 5574 older adults, 1683 (30%) had a large eGFR discordance. Those with a large eGFR discordance were more likely to be older, female, and White. The prevalence of a large eGFR discordance increased with age, from 20% among those 65–69 years to 44% among those 80 years and older. Over a 2-year follow-up, there were 305 deaths (5.5%), 2013 falls (39.2%), 69 hip fractures (1.3%), and 1649 hospitalizations (32.2%). In adjusted analyses, large eGFR discordance was associated with a higher hazard ratio for death (hazard ratio, 1.43; 95% confidence interval [CI], 1.12 to 1.82) and significantly higher odds of falls (odds ratio, 1.32; 95% CI, 1.16 to 1.51) and hospitalizations (odds ratio, 1.32; 95% CI, 1.15 to 1.51). A large eGFR discordance was not associated with hip fractures.

Conclusions

In a large, nationally representative cohort of older adults, prevalence of eGFR discordance increased with age and was associated with higher risk of falls, hospitalization, and death, independent of kidney function.

Pathways in formulating foods for the elderly

The growth of the elderly population worldwide is posing significant challenges to human society. The progressive physical and physiological changes occur with aging, including decreased appetite, incomplete digestion, and reduced absorption of nutrients. A common feature of many elderly people's diets is a deficiency in proteins (especially easily digestible ones) and micronutrients (e.g., vitamins, zinc, iron, and calcium). One of the solutions to this problem is the incorporation of these components into suitably texture-modified foods. There is a dearth of products that meet the needs of the elderly with special medical/health conditions such as dysphagia, osteoporosis, diabetes, and cardiovascular disease, as well as those who are in hospital and palliative care. Future research and development of foods for the elderly must address specific dietary needs of different subgroups of elderly people with underlying health conditions. The existence of different physical and physiological stages of the elderly means that their specific dietary requirements must be considered. This review summarizes current knowledge on nutritional requirements including those with underlying health problems and outlines the research and innovation pathways for developing new foods considering nutrition, texture, flavor, and other sensory aspects.

Nutrition as the foundation for successful aging: a focus on dietary protein and omega-3 polyunsaturated fatty acids

Skeletal muscle plays a critical role throughout the aging process. People living with sarcopenia, a progressive and generalized loss of skeletal muscle mass and function, often experience diminished quality of life, which can be attributed to a long period of decline and disability. Therefore, it is important to identify modifiable factors that preserve skeletal muscle and promote successful aging (SA). In this review, SA was defined as (1) low cardiometabolic risk, (2) preservation of physical function, and (3) positive state of wellbeing, with nutrition as an integral component. Several studies identify nutrition, specifically high-quality protein (eg, containing all essential amino acids), and long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), as positive regulators of SA. Recently, an additive anabolic effect of protein and n-3 PUFAs has been identified in skeletal muscle of older adults. Evidence further suggests that the additive effect of protein and n-3 PUFAs may project beyond skeletal muscle anabolism and promote SA. The key mechanism(s) behind the enhanced effects of intake of protein and n-3 PUFAs needs to be defined. The first objective of this review is to evaluate skeletal muscle as a driver of cardiometabolic health, physical function, and wellbeing to promote SA. The second objective is to examine observational and interventional evidence of protein and n-3 PUFAs on skeletal muscle to promote SA. The final objective is to propose mechanisms by which combined optimal intake of high-quality protein and n-3 PUFAs likely play a key role in SA. Current evidence suggests that increased intake of protein above the Recommended Dietary Allowance and n-3 PUFAs above the Dietary Guidelines for Americans recommendations for late middle-aged and older adults is required to maintain skeletal muscle mass and to promote SA, potentially through the mechanistical target of rapamycin complex 1 (mTORC1).

The Influence of the Mediterranean Dietary Pattern on Osteoporosis and Sarcopenia

Diet is a modifiable factor in bone and muscle health. The Mediterranean diet (MedDiet) is rich in nutrients and contains key bioactive components with probable protective effects on muscle and bone deterioration. Osteoporosis (OP) and sarcopenia are diseases that increase frailty and susceptibility to fracture, morbidity and mortality. Therefore, it is necessary to combat them in the population. In this regard, MedDiet adherence has proven to be beneficial to bone mineral density (BMD), muscle mass, physical function, OP and sarcopenia. Hence, this diet is proposed as a therapeutic tool that could slow the onset of osteoporosis and sarcopenia. However, there is doubt about the interaction between the MedDiet, strength and fracture risk. Perhaps the amount of EVOO (extra virgin olive oil), fruits, vegetables and fish rich in anti-inflammatory and antioxidant nutrients ingested has an influence, though the results remain controversial.

Mediterranean Diet and Sarcopenia Features in Apparently Healthy Adults over 65 Years: A Systematic Review

Low muscle mass combined with changes in physical function and muscle quality is defined as sarcopenia. In people > 60 years, sarcopenia reaches 10% and tends to increase with age. Individual nutrients, such as protein, may have a protective role against sarcopenia, but recent evidence suggests that protein alone has been ineffective in increasing muscle strength. Dietary patterns, instead, with a high "anti-inflammatory" potential, such as the Mediterranean dietary pattern, have been considered as an emerging dietary remedy against sarcopenia. The aim of this systematic review was to summarize the evidence of the role of Mediterranean diet in sarcopenia prevention and/or improvement, including recent data, in healthy elders. We searched published studies about sarcopenia and the Mediterranean diet until December 2022 in Pubmed, Cochrane, Scopus search engine and grey literature. In total, ten articles were identified as relevant: four cross-sectional studies and six prospective. No clinical trial was identified. Only three studies assessed sarcopenia presence and four measured muscle mass, which is an essential criterion in sarcopenia diagnosis. Mediterranean diet adherence had, in general, a positive role in muscle mass and muscle function, while the results were less clear with regard to muscle strength. Additionally, there was no evidence of a positive effect of the Mediterranean diet on sarcopenia. There is a need for conduction of clinical trials in order to reach cause-effects conclusions regarding the importance of the Mediterranean diet in sarcopenia prevention and management in Mediterranean and non-Mediterranean populations.

Differential plasma protein expression after ingestion of essential amino acid-based dietary supplement verses whey protein in low physical functioning older adults

In a recent randomized, double-blind, placebo-controlled trial, we were able to demonstrate the superiority of a dietary supplement composed of essential amino acids (EAAs) over whey protein, in older adults with low physical function. In this paper, we describe the comparative plasma protein expression in the same subject groups of EAAs vs whey. The plasma proteomics data was generated using SOMA scan assay. A total of twenty proteins were found to be differentially expressed in both groups with a 1.5-fold change. Notably, five proteins showed a significantly higher fold change expression in the EAA group which included adenylate kinase isoenzyme 1, casein kinase II 2-alpha, Nascent polypeptide-associated complex subunit alpha, peroxiredoxin-1, and peroxiredoxin-6. These five proteins might have played a significant role in providing energy for the improved cardiac and muscle strength of older adults with LPF. On the other hand, fifteen proteins showed slightly lower fold change expression in the EAA group. Some of these 15 proteins regulate metabolism and were found to be associated with inflammation or other comorbidities. Gene Ontology (GO) enrichment analysis showed the association of these proteins with several biological processes. Furthermore, protein-protein interaction network analysis also showed distinct networks between upregulated and downregulated proteins. In conclusion, the important biological roles of the upregulated proteins plus better physical function of participants in the EAAs vs whey group demonstrated that EAAs have the potential to improve muscle strength and physical function in older adults. This study was registered with ClinicalTrials.gov: NCT03424265 "Nutritional interventions in heart failure."

Health-related quality of life and its association with socioeconomic status and diet diversity in Chinese older adults

Objectives

The study aimed at examining the combined association of socioeconomic status (SES) and diet diversity (DD) with health-related quality of life (HRQoL) and exploring whether DD played a mediating role in the relationship between varied SES and HRQoL among Chinese older persons.

Method

A multi-stage random sampling method was conducted in Shanxi Province of China, with 3,250 older adults participating in this cross-sectional survey. SES was divided into groups by quartiles and DD by means, and these variable groups were combined in pairs to generate a total of eight combinations. The PROCESS macro developed by Hayes was employed for the simple mediation analysis.

Results

Compared with the reference group (those with both high SES and high DD), older adults who were classified to have lower SES or DD had elevated odds of having worse HRQoL: low SES/ low DD (OR = 1.65, 95% CI 1.41-2.92); low SES/ high DD (OR = 1.45, 95% CI 1.17-1.80); middle low SES/ low DD (OR = 1.43, 95% CI 1.24-1.65); middle low SES/ high DD (OR = 1.23, 95% CI 1.03-1.47); upper high SES/ low DD (OR = 1.41, 95% CI 1.21-1.65); and high SES/ low DD (OR = 1.30, 95%CI 1.10-1.53). The mediation analysis revealed that DD mediated the relationship between SES and HRQoL (B=0.011, 95% CI 0.008-0.013), with its indirect effects accounting for 39.29% of the total effects.

Conclusions

These findings highlighted the role of DD as a mediator of the relationship between SES and HRQoL. As DD could be protective, modifiable, and easy for older adults to understand and implement, village clinics and community health stations should work collaboratively to design proper DD intervention measures for better HRQoL.

Association between the Intake of Different Protein Sources and Obesity Coexisting with Low Handgrip Strength in Persons near Retirement Age

Nutrition is important for preventing and treating sarcopenic obesity/SO, proteins play a fundamental role. This study aimed at (1) identifying the association between different protein sources, other factors, and obesity coexisting with low handgrip strength and (2) evaluating differences in protein intake between persons with coexistence of obesity with low handgrip strength, obesity alone, low handgrip strength alone and persons neither obese nor having low handgrip strength. This study is a secondary data analysis of SHARE-data among 5362 persons near retirement age. We used descriptive statistics, statistical tests and univariate and multiple logistic regression analyses. Prevalence of obesity coexisting with low handgrip strength was 4.8%. Participants with low handgrip strength had the significantly lowest intake of all protein groups, followed by participants with obesity and low handgrip strength (p < 0.001). Daily intake of meat/fish (0.56, CI 0.40−0.79), age (1.07, CI 1.03−1.11), two or more chronic diseases (2.22, CI 1.69−2.93), one or more limitations concerning instrumental activities of daily living (2.23, CI 1.60−3.11), and moderate activity more than once a week (0.44, CI 0.33−0.57) were significantly related factors regarding obesity coexisting with low handgrip strength. Findings suggest that a daily intake of meat/fish is associated with lower odds of suffering from obesity with low handgrip strength in retirement-aged persons. Further studies are needed for specific recommendations regarding different protein sources for obese persons with low muscle mass and/or strength.

The potential role of beef and nutrients found in beef on outcomes of wellbeing in healthy adults 50 years of age and older: A systematic review of randomized controlled trials

Shifts in wellbeing and health occur as we age. As life expectancy increases, maintenance of wellbeing and health becomes increasingly important. Nutrients found in beef are associated with outcomes of wellbeing such as physical and cognitive function, lean body mass, and mood in older adults and individuals with chronic disease. However, it is unclear how beef and nutrients found in beef impact wellbeing in healthy adults ≥50 years of age. This study systematically reviewed evidence linking the intake of beef and nutrients found in beef to markers of wellbeing in healthy adults. PubMed, CINAHL, and Web of Science were searched up to August 31, 2021 for eligible randomized controlled trials (RCTs). Nutrients included in the analysis were beef, red meat, dietary protein, essential amino acids, branched chain amino acids, tryptophan, arginine, cysteine, glycine, glutamate, vitamin B6, vitamin B12, choline, zinc, and iron. We identified nine RCTs with results from 55 measurements of markers of wellbeing. An overall positive effect was found of beef and beef's nutrients on wellbeing. There was an overall positive effect of amino acids and protein on wellbeing, with no effect of arginine, vitamin B-12, leucine, and zinc. Physical function was also influenced by beef and nutrients found in beef. Eight of the studies found focused on specific nutrients found in beef, and not beef itself in older adults with one or more chronic diseases. This study identified a need for further research regarding the effect of beef and nutrients found in beef on defined functional outcomes of wellbeing in healthy adults ≥50 years of age.

Healthy Eating Is Associated with Sarcopenia Risk in Physically Active Older Adults

Healthy Diet and physical activity may play important roles in the maintenance of muscle health during aging. The aim of the present study was to explore the impact of adherence to healthy dietary patterns on sarcopenia risk in a sample of physically active older men and women, while considering adherence to guidelines on muscle strengthening activities (MSA) and protein intake. Based on a sample of 191 physically active men and women (65-70 years), dietary intake was assessed using a 90-items food-frequency-questionnaire (FFQ) and Healthy Diet Score (HDS) was calculated. Physical activity was assessed by accelerometry and self-report. A sarcopenia risk score (SRS) was derived based on three indicators of muscle health: muscle mass was assessed using bioelectrical impedance and handgrip strength and 5 times sit-to-stand (5-STS) were determined by standardized procedures. Analysis of covariance (ANCOVA) was used to examine differences in SRS and its components across sex-specific tertiles of HDS, with adjustments for covariates including total energy intake, protein intake and MSA. A significant main effect (p < 0.05) of HDS on SRS was observed, where those belonging to the highest HDS tertile had lower SRS compared to those in the lowest tertile. A corresponding significant effect was observed for 5-STS performance, with better performance in those with the highest HDS adherence compared to those with the lowest. The present study supports guidelines emphasizing diet quality beyond amounts of macro- and micronutrients in the prevention of age-related deterioration of muscle health. Importantly, the benefits from healthy dietary patterns are evident in older adults who already adhere to guidelines for health-enhancing physical activity.

Effects of Quality and Quantity of Protein Intake for Type 2 Diabetes Mellitus Prevention and Metabolic Control

PURPOSE OF REVIEW

The aim of this review is to evaluate the ideal protein quality and quantity and the dietary composition for the prevention and metabolic control of type 2 diabetes mellitus (T2DM).

INTRODUCTION

Although some reviews demonstrate the advantages of a diet with a higher protein intake, other reviews have observed that a diet high in carbohydrates, with low-glycaemic index carbohydrates and good fibre intake, is equally effective in improving insulin sensitivity.

METHODS

Over 2831 articles were screened, and 24 from the last 5 years were analysed and summarised for this review, using the protein, diabetes and insulin glucose metabolic keywords in Pubmed in June 2019.

RESULTS

Eleven studies demonstrate that a higher consumption of proteins has a positive effect on insulin sensitivity. A higher intake of animal protein seems to be related to an increased risk of T2DM. Four studies show that consumption of meat has a deleterious effect. Higher intake of plant protein and dairy products is associated with a modestly reduced risk.

DISCUSSION

Based on the results obtained, for the prevention of T2DM and all disorders related to metabolic syndrome, no ideal dietary composition has yet been found. The advantage of plant protein sources may be related to the foods' low-glycaemic index due to the high fibre content. However, the right protein quality (animal and plant) and the quantity for T2DM prevention and metabolic control are unclear and need to be investigated with further long-term studies.

Association between dietary protein intake and skeletal muscle mass in older Korean adults

PURPOSE

We investigated the association of low and high daily protein intakes on skeletal muscle mass status in Korean adults aged 60 years and older.

METHODS

This cross-sectional study used data from the Korean National Health and Nutrition Examination Survey conducted between 2008 and 2011. The participants' dietary protein intake was assessed using the 24-h dietary recall method and was classified as low (< 0.8 g/kg body weight/day), moderate (0.8-1.2 g/kg/day), and high (> 1.2 g/kg/day). Amount of skeletal muscle mass was measured using whole-body dual-energy X-ray absorptiometry. Low skeletal muscle mass was defined as appendicular skeletal muscle mass index < 7.0 kg/m² in men and < 5.4 kg/m² in women.

RESULTS

The study included data from 4585 participants (2022 men and 2563 women). All skeletal muscle parameters in women and total lean mass in men decreased as the amount of protein consumed daily increased. However, there was no association between high or low protein intake and low skeletal muscle mass in men or women.

CONCLUSIONS

No association was found between the amount of daily protein intake and skeletal muscle mass status in older Korean adults. Gender-specific further studies focussing on the interactions of dietary protein intake under specific conditions including physical activity status and the daily distribution of protein intake and the quality and source of the protein are needed to evaluate the impact of protein intake status on muscle health in older Koreans.

Nutrition in Physical Therapist Practice: Setting the Stage for Taking Action

Diet and nutrition are critical components of health, recovery from disease and illness, performance, and normal growth across the lifespan. Thus, it is important for physical therapists to be knowledgeable about nutrition and to have competency in providing information and guidance to patients/clients. Yet, there is an overwhelming amount of diet and nutrition information available from numerous sources, which makes it difficult to reach conclusions and determine the importance and relevance to patient care. The purpose of this perspective paper is to increase the knowledge and skills of physical therapists by providing guidelines for healthy eating and outlining diet and nutrition information most relevant for physical therapist practice and to clarify professional scope of practice related to diet and nutrition, including boundaries created by law, and the connection between healthy eating and health outcomes, muscle strength, bone health, and wound healing.

Protein intake and loss of proteostasis in the eldery

Ageing is a process of declining bodily function and a major risk factor of chronic diseases. The declining bodily function in ageing can cause loss of proteostasis (protein homeostasis), which is a balance between protein synthesis, folding, modification and degradation. For the elderly, adequate protein intake is necessary to prevent sarcopenia, frailty, fracture and osteoporosis as well as reduced resistance to infection. However, increasing the protein intake can enhance the risk of oxidized protein formation, loss of proteostasis and degenerative disorder occurrence. On the other hand, several studies show that protein restriction would increase longevity. The aim of this review was to explain the importance of determining the right amount and composition of protein intake for the elderly. Oxidative stress and molecular mechanism of proteostasis loss in ageing cells as well as its suppression pathway by protein restriction are discussed in this review. Keywords: ageing, dietary proteins, mTOR, oxidative stress, proteostasis loss

Protein blend and casein supplementations before inactive phase similarly activate mechanistic target of rapamycin signaling in rat skeletal muscle

During overnight sleep, the longest postabsorptive and inactive phase of the day causes protein catabolism and loss. However, the daytime ingestion of dairy proteins has been shown to stimulate muscle protein synthesis and growth. This study compared the effects of pre-sleep supplementation of a protein blend (PB) composed of micellar casein (MCa) and whey protein (1:1) versus isolate MCa on the plasma levels of branched-chain amino acids (BCAAs) and the activation of the mechanistic target of rapamycin (mTOR) signaling, a critical intracellular pathway involved in the regulation of muscle protein synthesis. After 10 h of fasting during the active phase, rats were fed with a single dose of PB or MCa (5.6 g protein/kg of body mass) by gavage, and samples of blood and gastrocnemius muscle were collected at 30, 90, and 450 min. PB and MCa supplementations induced an increase (~3-fold, P < 0.001) of plasma BCAAs at 30 and 90 min. Most importantly, the stimulatory phosphorylation levels of mTOR and its downstream target p70 ribosomal protein S6 kinase (p70S6K) were similarly higher (~2.5-fold, P < 0.001) 30 and 90 min after MCa and PB. Plasma levels of leucine, isoleucine, valine, and overall BCAAs were correlated with the activation of mTOR (P < 0.001) and p70S6K (P < 0.001). MCa and PB supplementations before the inactive phase of rats resulted in an anabolic milieu in the skeletal muscle by inducing a transient increase in plasma BCAAs and a similar activation of the mTOR/p70S6K axis.

Attitudes and Approaches to Use of Meal Replacement Products among Healthcare Professionals in Management of Excess Weight

Meal replacement product-based diets are an effective weight loss intervention used in the management of obesity. Historically, these diets have been underutilised by HealthCare Professionals (HCPs). An online survey of mixed methods design was distributed to HCPs to capture current perceptions and prescribing patterns of meal replacement products (MRPs) in the management of overweight and obesity. A total of 303 HCPs working in weight management across Australia began the survey and 197 (65%) completed it. While over 70% of HCPs have prescribed MRP currently or in the past, MRPs are only prescribed to a median 7% of patients seeking weight management treatment. Qualitative analysis identified potential barriers to MRP prescription, which include experience with patient non-compliance, perceived poor long-term weight loss durability and safety concerns regarding the product and its use as a total meal replacement program. Safety concerns are centred on the perceived risk of weight cycling and its potential negative psychological impact. MRP prescription is 66% more likely to occur if HCPs had formal training in the use of MRPs relative to those who did not, with a relative risk (RR) of 1.7 (95% CI 1.4, 2.0). This study highlights the potential barriers to the prescription of MRPs, which are centred around safety concerns. This also indicates that formal training may enhance the likelihood of prescribing MRPs, suggesting that once HCPs have a comprehensive understanding of the products and the evidence behind their use, their prescription is likely to be increased.

Calorie Restriction and Aging in Humans

Calorie restriction (CR), the reduction of dietary intake below energy requirements while maintaining optimal nutrition, is the only known nutritional intervention with the potential to attenuate aging. Evidence from observational, preclinical, and clinical trials suggests the ability to increase life span by 1-5 years with an improvement in health span and quality of life. CR moderates intrinsic processes of aging through cellular and metabolic adaptations and reducing risk for the development of many cardiometabolic diseases. Yet, implementation of CR may require unique considerations for the elderly and other specific populations. The objectives of this review are to summarize the evidence for CR to modify primary and secondary aging; present caveats for implementation in special populations; describe newer, alternative approaches that have comparative effectiveness and fewer deleterious effects; and provide thoughts on the future of this important field of study.

Acute Effect of a Protein Supplement on Targeted Plasma Amino Acid Profile among Healthy Asian Indians: A Randomized Controlled Trial

BACKGROUND

Indians have a poor protein intake in terms of quantity as well as quality because of their predominantly cereal-based diet. However, there is limited information on circulatory amino acid levels in healthy Indians. Herein, we evaluated the acute effect of a protein supplement on the plasma levels of essential amino acids (EAAs) in healthy Indian adults, using targeted EAA analysis.

METHODS

In this double-blind, randomized, crossover study, 20 healthy Indian adults were randomized to receive the test protein supplement (treatment arm, n = 10) or placebo (control arm, n = 10) with milk, after overnight fasting. After 7 days, the participants returned for the crossover treatment. Blood samples were collected at baseline and at 60 and 120 min after protein/placebo consumption. Plasma EAA levels were estimated using liquid chromatography-tandem mass spectrometry. Repeated measures ANOVA was performed to assess the effect of treatment on EAA levels. P values < 0.05 were considered statistically significant.

RESULTS

At baseline, mean plasma levels did not differ significantly between the two arms for any of the EAAs. In the treatment arm, the mean levels of all EAAs increased significantly from baseline to 60 min (P < 0.01), with no significant change from 60 to 120 min. There was no significant change in amino acid levels in the control arm. The magnitude as well as percentage of increase from baseline to 60 min was significantly greater in the treatment arm than in the control arm for all EAAs.

CONCLUSION

Compared to placebo, protein supplement increased circulatory amino acid levels in healthy Indians. The observed increase in EAA levels and its role in conjunction with exercise in both healthy and diseased states need to be further evaluated. This is the first dataset exploring targeted EAA profiles and the effect of a protein supplement among healthy Indians. The clinical trial is registered with CTRI/2018/12/016777.

Sarcopenia: A Contemporary Health Problem among Older Adult Populations

Sarcopenia, a geriatric disease characterized by a progressive loss of skeletal muscle mass and loss of muscle function, constitutes a rising, often undiagnosed health problem. Its prevalence in the elderly population is largely considered variable, as it ranges from 5% to 50% depending on gender, age, pathological conditions as well as diagnostic criteria. There is no one unified approach of treatment or assessment, which makes sarcopenia even harder to assess. There is a pressing need to provide better diagnosis, diagnostics, prevention, and individualized health care. Physical activity and nutrition are the main studied ways to prevent sarcopenia, and they also offer better outcomes. This review aims to report the prevalence of sarcopenia in older adults, its etiology, prevention, and treatment techniques.

The Short-Term Effect of Whey Compared with Pea Protein on Appetite, Food Intake, and Energy Expenditure in Young and Older Men

BACKGROUND

Diets higher in protein have been reported to improve age-related changes in body composition via increased energy expenditure, shifts in substrate oxidation (SO), and decreased appetite. However, how protein source (e.g., animal compared with plant protein) affects energy expenditure, appetite, and food intake as we age is unknown.

OBJECTIVES

The objective of this study was to evaluate the effect of protein source as part of a high-protein breakfast on appetite, food intake, energy expenditure, and fat oxidation in young men (YM) compared with older men (OM).

METHODS

This study used a randomized, single-blinded crossover design, with a 1-wk washout period between testing days. Fifteen YM (mean ± SD age: 25.2 ± 2.8 y) and 15 OM (67.7 ± 4.5 y), healthy adults, participated in the study. Participants arrived fasted and consumed an isocaloric, volume-matched, high-protein (40-g) test beverage made with either an animal [whey protein isolate (WPI)] or plant [pea protein isolate (PPI)] protein isolate source. Markers of appetite and energy expenditure were determined at baseline and over 4 h postprandial.

RESULTS

There was a significant effect of time, age, and protein source on appetite (P < 0.05). There was no effect of protein source on plasma markers of appetite, food intake, energy expenditure, and SO. After controlling for body weight, OM had decreased energy expenditure (P < 0.05) and lower fat oxidation (P < 0.001) compared with YM.

CONCLUSIONS

This study indicates that a high-protein breakfast containing WPI or PPI exerts comparable effects on appetite, energy expenditure, and 24-h energy intake in both young and older healthy adult men.This trial was registered at clinicaltrials.gov as NCT03399812.

Optimal Protein Intake during Weight Loss Interventions in Older Adults with Obesity

Obesity rates in people 60 years and older are increasing. While obesity is linked with detrimental health risks, weight loss in this population has previously been considered controversial due to potential worsening of age-related sarcopenia. Protein intake during energy restriction has been linked to lean body mass preservation. No formal guidelines for optimal protein intake during structured weight loss interventions exist for this population, but it appears that the current Recommended Dietary Allowance of 0.8 grams per kilogram of body weight per day may be inadequate. The purpose of this review is to discuss optimal protein intake during structured weight loss interventions in persons 60 years and older with obesity and to present a framework for guidelines to be used by health professionals focusing on weight loss interventions in older adults. Goals for the amount, source, and timing of protein intake, from both food and supplements, are presented and discussed.

The Impact of Dairy Protein Intake on Muscle Mass, Muscle Strength, and Physical Performance in Middle-Aged to Older Adults with or without Existing Sarcopenia: A Systematic Review and Meta-Analysis

Sarcopenia is an age-related condition associated with a progressive loss of muscle mass and strength. Insufficient protein intake is a risk factor for sarcopenia. Protein supplementation is suggested to improve muscle anabolism and function in younger and older adults. Dairy products are a good source of high-quality proteins. This review evaluates the effectiveness of dairy proteins on functions associated with sarcopenia in middle-aged and older adults. Randomized controlled trials were identified using PubMed, CINAHL/EBSCO, and Web of Science databases (last search: 10 May 2017) and were quality assessed. The results of appendicular muscle mass and muscle strength of handgrip and leg press were pooled using a random-effects model. The analysis of the Short Physical Performance Battery is presented in narrative form. Adverse events and tolerability of dairy protein supplementation were considered as secondary outcomes. Fourteen studies involving 1424 participants aged between 61 and 81 y met the inclusion criteria. Dairy protein significantly increased appendicular muscle mass (0.13 kg; 95% CI: 0.01, 0.26 kg; P = 0.04); however, it had no effect on improvement in handgrip (0.84 kg; 95% CI: -0.24, 1.93 kg; P = 0.13) or leg press (0.37 kg; 95% CI: -4.79, 5.53 kg; P = 0.89). The effect of dairy protein on the Short Physical Performance Battery was inconclusive. Nine studies reported the dairy protein to be well tolerated with no serious adverse events. Although future high-quality research is required to establish the optimal type of dairy protein, the present systematic review provides evidence of the beneficial effect of dairy protein as a potential nutrition strategy to improve appendicular muscle mass in middle-aged and older adults.

Factors contributing to the selection of dietary protein food sources

Protein is the only dietary macronutrient required for life. As such, it is reasonable to consider dietary protein as the centerpiece of a healthy eating pattern. To do so requires consideration of what type of protein should be eaten. Account should be taken of the quality of the protein, the density of the protein in the protein food source, and the non-protein components of protein food source. The quality of protein can be quantified based on the amount and profile of essential amino acids (EAAs), as well as the true ileal digestibility of the EAAs in the protein. The density of protein in a food source can be quantified on the basis of the amount of total calories ingested to achieve intake of the daily requirement of all EAAs. Non-protein components of protein food sources can be considered in terms of the amount and nature of fat, carbohydrate and fiber, as well as the content of micronutrients. Potential beneficial effects of high-quality protein food sources should be balanced against any possible adverse effects. When all of these factors are considered we conclude that animal-based protein foods (e.g., eggs, dairy, meat, fish, poultry) occupy an important place in a healthy eating pattern.

Protein Consumption and the Elderly: What Is the Optimal Level of Intake?

Maintaining independence, quality of life, and health is crucial for elderly adults. One of the major threats to living independently is the loss of muscle mass, strength, and function that progressively occurs with aging, known as sarcopenia. Several studies have identified protein (especially the essential amino acids) as a key nutrient for muscle health in elderly adults. Elderly adults are less responsive to the anabolic stimulus of low doses of amino acid intake compared to younger individuals. However, this lack of responsiveness in elderly adults can be overcome with higher levels of protein (or essential amino acid) consumption. The requirement for a larger dose of protein to generate responses in elderly adults similar to the responses in younger adults provides the support for a beneficial effect of increased protein in older populations. The purpose of this review is to present the current evidence related to dietary protein intake and muscle health in elderly adults.