Low protein intake, physical activity, and physical function in European and North American community-dwelling older adults: a pooled analysis of four longitudinal aging cohorts

Plant protein, fibre and physical activity solutions to address poor appetite and prevent undernutrition in older adults: study protocol for the APPETITE randomised controlled trial

Reduced appetite with ageing is a key factor that may increase risk of undernutrition. The objective of this study is to determine the impact of innovative plant protein fibre (PPF) products within a personalised optimised diet (PD), a physical activity (PA) programme, and their combination on appetite, and other nutritional, functional and clinical outcomes in community-dwelling older adults in a multi-country randomised controlled intervention trial. One hundred and eighty community-dwelling adults (approximately sixty per trial centre in Germany, Ireland and Italy) aged 65 years and over will be recruited to participate in a 12-week, parallel-group, controlled trial. Participants will be randomised into one of four groups: 1, PD (incorporating two PPF products): 2, PA; 3, PD + PA; and 4, no intervention (control). The primary outcome is appetite measured by visual analogue scales and energy intake from an ad libitum test meal. Secondary outcomes include fasting and postprandial appetite-related gut hormones, Simplified Nutritional Appetite Questionnaire score, body composition, cardiorespiratory fitness, muscle strength, physical function and PA. In addition, self-efficacy, cognitive status, dietary restraint, depressive symptoms and compliance and acceptability of the intervention will be assessed. Metabolomic profiles, RMR, muscle motor unit properties and gut microbiome will also be assessed to explore potential underlying mechanisms. This multi-centre randomised controlled trial will advance knowledge on how PD (incorporating PPF products), PA and their combination influence appetite, nutritional status and related health outcomes in community-dwelling older adults and contribute to the prevention of undernutrition. Trial registration: Clinical Trials.gov Registry NCT05608707 (registered on 2 November 2022). Protocol Version: NCT05608707 Version 4 (registered on 29 September 2023).

Protein Intake and Physical Activity Levels as Determinants of Sarcopenia Risk in Community-Dwelling Older Adults

Community screening for sarcopenia is complex, with barriers including access to specialized equipment and trained staff to conduct body composition, strength and function assessment. In the current study, self-reported dietary protein intake and physical activity (PA) in adults ≥65 years was assessed relative to sarcopenia risk, as determined by body composition, strength and physical function assessments, consistent with the European Working Group on Sarcopenia in Older People (EWGSOP) definition. Of those screened (n = 632), 92 participants (77% female) were assessed as being at high risk of developing sarcopenia on the basis of dietary protein intake ≤1 g∙kg-1∙day-1 [0.9 (0.7-0.9) g∙kg-1∙day-1] and moderate intensity physical activity <150 min.week-1. A further 31 participants (65% female) were defined as being at low risk, with both protein intake [1.2 (1.1-1.5) g∙kg-1∙day-1] and PA greater than the cut-off values. High-risk participants had reduced % lean mass [53.5 (7.8)% versus 54.8 (6.1)%, p < 0.001] and impaired strength and physical function. Notably, high-risk females exhibited greater deficits in lean mass and strength, with minimal differences between groups for males. In community-dwelling older adults, self-reported low protein intake and low weekly PA is associated with heightened risk for sarcopenia, particularly in older women. Future research should determine whether early intervention in older adults with low protein intake and PA attenuates functional decline.

Association between soya food consumption and muscle strength in Chinese adolescents: evidence from a cross-sectional study

There is a strong association between soya food consumption and health, but there are few studies on the association with muscular strength, especially in adolescent groups. This study was conducted to understand the status of soya food consumption and its association with muscular strength among secondary school students in southern China. A stratified whole-group sampling method was used to investigate and test the status of soya food consumption and muscular strength of 13 220 secondary school students in southern China. Linear regression analysis and logistic regression analysis were used to analyse the correlations between soya food consumption and muscular strength. Logistic regression analysis showed that compared with secondary school students with soya food consumption ≥ 3 times/week, male students with soya food consumption ≤ 1 time/week (OR = 1·896, 95 % CI: 1·597,2·251) and female students with soya food consumption ≤ 1 time/week (OR = 2·877, 95 % CI: 2·399, 3·449) students had a higher risk of developing lower grip strength (P < 0·001). The frequency of soya food consumption among secondary school students in southern China was 49·00 %, 28·77 % and 22·23 % for ≥ 3 times/week, 2-3 times/week and ≤ 1 time/week, respectively. There is a positive association between soya food consumption and muscle strength among secondary school students in southern China. In the future, increasing the consumption of soybean products can be considered for the improvement of muscle strength.

Appetite and family and friends network among community-dwelling older adults: A cross-sectional study

OBJECTIVES

The aim of this study was to investigate the stronger correlate of appetite-family or friend networks-in community-dwelling older adults, given that undernutrition can impair physical function, increase mortality, and be influenced by social networks.

METHODS

A cross-sectional study was conducted in Kasugai City, Aichi Prefecture, and Nara City, Nara Prefecture, Japan, between August 2019 and March 2023. The analysis included 119 participants (women: 79%, mean age: 76.5 ± 5.6 y). A multiple regression analysis was performed, using the scores from the Japanese version of the Simplified Nutritional Appetite Questionnaire (SNAQ-J) as the dependent variable and family network and friend network as the independent variables. The analysis included social participation, living alone status, sex, age, body mass index, skeletal muscle mass index, grip strength, walking speed, and the Japanese version of the 15 Geriatric Depression Scale score as covariates to examine their relationship with appetite.

RESULTS

The mean value of the SNAQ-J score of the participants was 15.4 ± 1.2. Seven participants (6%) had a loss of appetite. Family network was significantly associated with appetite (B = 0.121, β = 0.266, P <0.05; 95% condidence interval [CI], 0.030-0.212). In the single regression analysis, the friend network was significantly associated with the total score of the SNAQ-J (B = 0.115, P <0.001; 95% CI, 0.052-0.177); however, this association was not observed in the multiple regression analysis (B = 0.002, β = 0.006, P = 0.954; 95% CI, -0.074-0.078).

CONCLUSION

Appetite was associated with family networks. Among social networks, focusing on family networks may help prevent the loss of appetite in older adults in Japan.

Protein - a scoping review for Nordic Nutrition Recommendations 2023

Proteins are needed for providing essential amino acids, nitrogen, and fuel for the body's needs in all age groups. Proteins are especially required during active growth in pregnancy, lactation, childhood, and tissue growth in general. An adequate protein intake is needed in old adults to avoid premature muscle loss. According to the current dietary surveys, protein intake in the Nordic and Baltic countries varies from 15 to 19% of the total energy intake in adults. Comprehensive data regarding children and older adults are lacking. No good measure for protein status exists, and the estimation of physiological requirements is based on N-balance studies having some weaknesses. Protein quality is assessed by considering the protein digestibility of individual indispensable amino acids and their utilization (bioavailability), which is affected by food antinutrients and processing. The evidence regarding the association of protein intake per se with health outcomes is limited or suggestive. It is difficult to separate from the effect of other nutrients or ingredients in protein-rich foods. Proteins are widespread in foods, deriving from both animal and plant sources. Animal-sourced protein production puts more strain on the environment than plant-sourced proteins and contributes significantly to greenhouse gas emissions, thereby enhancing climate change. In Nordic and Baltic countries, consumption of animal-sourced proteins is relatively high. A shift toward more plant-based protein diets would be advisable for promoting a healthy and sustainable diet.

The Health, Aging, and Body Composition (Health ABC) Study-Ground-Breaking Science for 25 Years and Counting

BACKGROUND

The Health, Aging, and Body Composition Study is a longitudinal cohort study that started just over 25 years ago. This ground-breaking study tested specific hypotheses about the importance of weight, body composition, and weight-related health conditions for incident functional limitation in older adults.

METHODS

Narrative review with analysis of ancillary studies, career awards, publications, and citations.

RESULTS

Key findings of the study demonstrated the importance of body composition as a whole, both fat and lean mass, in the disablement pathway. The quality of the muscle in terms of its strength and its composition was found to be a critical feature in defining sarcopenia. Dietary patterns and especially protein intake, social factors, and cognition were found to be critical elements for functional limitation and disability. The study is highly cited and its assessments have been widely adopted in both observational studies and clinical trials. Its impact continues as a platform for collaboration and career development.

CONCLUSIONS

The Health ABC provides a knowledge base for the prevention of disability and promotion of mobility in older adults.

Optimizing the Design of Clinical Trials to Evaluate the Efficacy of Function-Promoting Therapies

BACKGROUND

Several candidate molecules that may have application in treating physical limitations associated with aging and chronic diseases are in development. Challenges in the framing of indications, eligibility criteria, and endpoints and the lack of regulatory guidance have hindered the development of function-promoting therapies.

METHODS

Experts from academia, pharmaceutical industry, National Institutes of Health (NIH), and Food and Drug Administration (FDA) discussed optimization of trial design including the framing of indications, eligibility criteria, and endpoints.

RESULTS

Mobility disability associated with aging and chronic diseases is an attractive indication because it is recognized by geriatricians as a common condition associated with adverse outcomes, and it can be ascertained reliably. Other conditions associated with functional limitation in older adults include hospitalization for acute illnesses, cancer cachexia, and fall injuries. Efforts are underway to harmonize definitions of sarcopenia and frailty. Eligibility criteria should reconcile the goals of selecting participants with the condition and ensuring generalizability and ease of recruitment. An accurate measure of muscle mass (eg, D3 creatine dilution) could be a good biomarker in early-phase trials. Performance-based and patient-reported measures of physical function are needed to demonstrate whether treatment improves how a person lives, functions, or feels. Multicomponent functional training that integrates training in balance, stability, strength, and functional tasks with cognitive and behavioral strategies may be needed to translate drug-induced muscle mass gains into functional improvements.

CONCLUSIONS

Collaborations among academic investigators, NIH, FDA, pharmaceutical industry, patients, and professional societies are needed to conduct well-designed trials of function-promoting pharmacological agents with and without multicomponent functional training.

Protein and Leucine Intake at Main Meals in Elderly People with Type 2 Diabetes

Background: The recommended protein intake for the elderly is 25–30 g at main meals, with at least 2500–2800 mg of leucine at each meal. There is still little evidence regarding the amount and distribution of protein and leucine intake with meals in the elderly with type 2 diabetes (T2D). In this cross-sectional study, we evaluated protein and leucine intake at each meal in elderly patients with T2D. Methods: A total of 138 patients (91 men and 47 women) with T2D, aged 65 years or older, were included. Participants performed three 24-h dietary recalls for the evaluation of their dietary habits and protein and leucine intake at meals. Results: The average protein intake was 0.9 ± 0.2 g/kg body weight/day, and only 23% of patients complied with the recommendations. The average protein intake was 6.9 g at breakfast, 29 g at lunch, and 21 g at dinner. None of the patients reached the recommended protein intake at breakfast; 59% of patients complied with the recommendations at lunch; and 32% at dinner. The average leucine intake was 579 mg at breakfast, 2195 g at lunch, and 1583 mg at dinner. The recommended leucine intake was not reached by any patient at breakfast, by 29% of patients at lunch, and by 13% at dinner. Conclusions: Our data show that, in elderly patients with T2D, the average protein intake is low, particularly at breakfast and dinner, and that leucine intake is remarkably lower than the recommended levels. These data raise the need to implement nutritional strategies capable of increasing protein and leucine intake in the elderly with T2D.

Relation Between Dietary Protein Intake and Gut Microbiome Composition in Community-Dwelling Older Men: Findings from the Osteoporotic Fractures in Men Study (MrOS)

BACKGROUND

Little is known about the association of specific nutrients, especially proteins, on age-related gut dysbiosis.

OBJECTIVES

To determine the associations between the quantity and sources (vegetable and animal) of dietary protein intake and gut microbiome composition in community-dwelling older men.

METHODS

We performed a cross-sectional analysis on 775 older men from the Osteoporotic Fractures in Men Study (MrOS) (age 84.2 ± 4.0 y) with available dietary information and stool samples at visit 4 (2014-2016). Protein intake was estimated from a brief FFQ and adjusted to total energy intake. The gut microbiome composition was determined by 16S (v4) sequencing (processed by DADA2 and SILVA). A total of 11,534 amplicon sequence variants (ASVs) were identified and assigned to 21 phyla with dominance of Firmicutes (45%) and Bacteroidetes (43%). We performed α-diversity, β-diversity, and taxa abundance (by Analysis of Compositions of Microbiomes with Bias Correction [ANCOM-BC]) to determine the associations between protein intake and the gut microbiome.

RESULTS

Median protein intake was 0.7 g/(kg body weight · d). Participants with higher energy-adjusted protein intakes had higher Shannon and Chao1 α-diversity indices (P < 0.05). For β-diversity analysis, participants with higher protein intakes had a different center in weighted and unweighted UniFrac Principal Co-ordinates Analysis (PCoA) compared with those with lower intake (P < 0.05), adjusted for age, race, education, clinical center, batch number, fiber and energy intake, weight, height, and medications. Similarly, higher protein consumptions from either animal or vegetable sources were associated with higher gut microbiome diversity. Several genus-level ASVs, including Christensenellaceae, Veillonella, Haemophilus, and Klebsiella were more abundant in participants with higher protein intakes, whereas Clostridiales bacterium DTU089 and Desulfovibrio were more abundant in participants with lower protein intake (Bonferroni corrected P < 0.05).

CONCLUSIONS

We observed significant associations between protein intake and gut microbiome diversity in community-living older men. Further studies are needed to elucidate the mediation role of the gut microbiome on the relation between protein intake and health outcomes in older adults.

Association of Dietary Protein Intake with Muscle Mass in Elderly Chinese: A Cross-Sectional Study

Most data regarding the association between dietary protein intake and muscle mass come from developed Western countries. This cross-sectional study investigates the association between the amount and distribution of dietary protein intake and muscle mass in elderly Chinese adults. This analysis includes 4826 participants aged 60 years and above from the dataset of the China Health and Nutrition Survey (CHNS) 2018. Protein intake data were assessed using 3-day, 24 h dietary recalls. Appendicular skeletal muscle mass (ASM) was obtained using the bioelectrical impedance analysis (BIA). Two-thirds of dietary protein intake comes from plant sources in the elderly Chinese population. The median total dietary protein intake was 60.5 g/d in low muscle mass participants for males and 52.5 g/d for females, which was lower than for their respective counterparts. Compared to the lowest quartile of protein intake, the highest total protein intake group had increased muscle mass by 0.96 kg among men and by 0.48 kg among women (p < 0.0001), and the highest vegetable protein intake group had increased muscle mass by 0.76 kg among men and by 0.35 kg among women (p < 0.0001). The amount of dietary protein intake with each meal was less than 20 g. High total protein intake and high plant-based protein intake were positively associated with higher muscle mass. A U-shape was observed between total dietary protein intake and low muscle mass risk in elderly Chinese adults. It should be encouraged to increase total daily protein intake to maintain muscle health.

Effect of personalized dietary advice to increase protein intake on food consumption and the environmental impact of the diet in community-dwelling older adults: results from the PROMISS trial

PURPOSE

Diet modelling studies suggest that increasing protein intake with no consideration for sustainability results in a higher environmental impact on the diet. To better understand the impact in real life, the aim of this study was to assess the effect of dietary advice to increase protein intake on food consumption and the environmental impact of the diet in community-dwelling older adults.

METHODS

Food consumption and environmental impact were analyzed among 124 Dutch older adults with lower habitual protein intake (< 1.0 g/kg adjusted body weight/day) participating in the six-month PROMISS trial. Dietary intake data from three 24-h dietary recalls, aided by food diaries, and results from life cycle assessments were used to examine the differences in changes in food consumption and environmental impact between those who received dietary advice to isocalorically increase protein intake to ≥ 1.2 g/kg aBW/d (Protein + ; n = 84) and those who did not receive dietary advice (Control; n = 40).

RESULTS

Compared to the Control, Protein + increased protein intake from animal-based food products (11.0 g protein/d, 95% CI 6.6-15.4, p < 0.001), plant-based food products (2.1 g protein/d, 95% CI 0.2-4.0, p = 0.031) and protein-enriched food products provided during the trial (18 g protein/d, 95% CI 14.5-21.6, p < 0.001) at the 6-month follow-up. Diet-associated greenhouse gas emissions increased by 16% (p < 0.001), land use by 19% (p < 0.001), terrestrial acidification by 20% (p = 0.01), and marine eutrophication by 16% (p = 0.035) in Protein + compared to the Control.

CONCLUSION

This study found that dietary advice increased protein intake, favoring animal-based protein, and increased the environmental impact of the diet in older adults.

TRIAL REGISTRATION

ClinicalTrials.gov. NCT03712306. October 2018.

Association of Plant Protein Intake with Change in Physical Performance in Chinese Community-Dwelling Older Adults

(1) Background: Dietary protein intake might be beneficial in optimizing physical performance, yet whether this is dependent on protein source and sex is unclear. We examined the association between dietary protein intake and change in physical performance among Chinese community-dwelling older adults. (2) Methods: This prospective study included older Chinese adults (≥65 years) in Hong Kong. Total, plant and animal protein intakes at baseline were assessed using a food frequency questionnaire. Physical performance at baseline and 4-year follow-up were assessed by the time to complete a 6-m walking test. Adjusted linear regression examined the association between total, plant and animal protein intakes (g/kg of body weight (BW)) and 4-year change in physical performance. (3) Results: 3133 participants (49.8% males) aged 71.8 ± 4.9 years were included. In males, total, plant and animal protein intakes were not associated with a change in physical performance. In females, higher plant protein intake was associated with less decline in physical performance (β 0.723, SE 0.288, p = 0.012). No associations were observed for total animal protein intakes. (4) Conclusion: In Chinese community-dwelling older adults, total and animal protein intakes were not associated with a 4-year change in physical performance. Higher plant protein intake was associated with less decline in physical performance in females.

Animal foods and mobility limitations in community-dwelling young-old adults: longitudinal analysis of the EpiDoC cohort

Background

Nutrition and particularly protein play a role in optimally stimulating muscle protein synthesis and maintaining function. Animal foods are excellent sources of high-quality protein. Therefore, we aimed to determine the association between the consumption of animal foods and mobility limitations in young-old adults.

Methods

The analytic sample was composed of 2860 community-dwelling adults aged 50 and over from a nationally representative longitudinal cohort of Portuguese adults who were followed up to 2.7 years. An animal food intake score was derived from the frequency of consumption of meat, fish, and dairy products. Mobility limitations were defined as the difficulty standing up from a chair, walking, and climbing stairs. To determine the association between animal food intake and mobility limitations mixed effects logistic models were fitted.

Results

Associations between quartiles of animal food intake and mobility limitations (for example, for walking outdoors Quartile 4 v Q1: OR: 0.29; 95%CI: 0.15, 0.56) in unadjusted models were present, but there was no difference in the rate of change of mobility limitations over time in unadjusted models. These associations were no longer present when models were adjusted for sociodemographic, lifestyle and health variables. For example, participants in Q4 of animal food intake were not more or less likely to have difficulty climbing stairs than those in Q1 (OR: 0.95; 95%CI: 0.65, 1.38) nor have a different rate of change over time (OR: 0.86; 95%CI: 0.54, 1.37).

Conclusions

No convincing evidence was found to support an effect of animal foods intake measured at baseline on self-reported mobility limitations over a short period of time.

Protein intake, physical activity and grip strength in European and North American community-dwelling older adults: a pooled analysis of individual participant data from four longitudinal ageing cohorts

INTRODUCTION

Higher dietary protein, alone or in combination with physical activity (PA), may slow the loss of age-related muscle strength in older adults. We investigated the longitudinal relationship between protein intake and grip strength, and the interaction between protein intake and PA, using four longitudinal ageing cohorts.

METHODS

Individual participant data from 5584 older adults (52% women; median: 75, IQR: 71.6, 79.0 years) with up to 8.5 years (mean: 4.9, SD: 2.3 years) of follow-up from the Health ABC, NuAge, LASA and Newcastle 85+ cohorts were pooled. Baseline protein intake was assessed with food frequency questionnaires and 24h recalls and categorized into <0.8, 0.8-<1.0, 1.0-<1.2 and ≥1.2 g/kg adjusted body weight (aBW)/d. The prospective association between protein intake, its interaction with PA, and grip strength (sex- and cohort-specific) was determined using joint models (hierarchical linear mixed effects and a link function for Cox proportional hazards models).

RESULTS

Grip strength declined on average by 0.018 SD (95%CI: -0.026, -0.006) every year. No associations were found between protein intake, measured at baseline, and grip strength, measured prospectively, or rate of decline of grip strength in models adjusted for sociodemographic, anthropometric, lifestyle and health variables (e.g., protein intake ≥1.2 vs <0.8 g/kg aBW/d: β= -0.003, 95%CI: -0.014,0.005 SD per year). There also was no evidence of an interaction between protein intake and PA.

CONCLUSIONS

We failed to find evidence in this study to support the hypothesis that higher protein intake, alone or in combination with higher PA, slowed the rate of grip strength decline in older adults.

Nutritional Status Association With Sarcopenia in Patients Undergoing Maintenance Hemodialysis Assessed by Nutritional Risk Index

Background

Malnutrition and sarcopenia are frequently observed in patients undergoing maintenance hemodialysis (MHD). To elucidate whether malnutrition is associated with sarcopenia in those cases, the relationship of nutritional status with sarcopenia was investigated.

Methods

Nutritional status was assessed using a nutritional risk index (NRI) developed for patients undergoing MHD. This retrospective cross-sectional study included 315 MHD patients (199 males, 116 females), who were divided into low-risk (score 0–7) and medium-/high-risk (score 8–13) groups. Sarcopenia and severe sarcopenia, along with low muscle mass, low muscle strength, and low physical performance were defined using the Asian Working Group for Sarcopenia 2019 criteria.

Results

The median NRI score was 5.0, while the prevalence of medium-/high-risk cases among the patients was 31.1%. Additionally, the rates of those with low muscle mass, low muscle strength, and low physical performance were 55.9, 60.6, and 31.4%, respectively, while those of sarcopenia and severe sarcopenia were 44.1 and 20.0%, respectively. Multivariable logistic regression analyses revealed a significant (P < 0.001) association of NRI score with sarcopenia [odds ratio (OR) 1.255, 95% confidence interval (CI) 1.143–1.377] and severe sarcopenia (OR 1.257, 95% CI 1.122–1.407), as well as low muscle mass (OR 1.260, 95% CI 1.157–1.374), low muscle strength (OR 1.310, 95% CI 1.178–1.457), and low physical performance (OR 1.216, 95% CI 1.104–1.339). Furthermore, medium-/high-risk status showed a significant (P < 0.05) association with sarcopenia (OR 2.960, 95% CI 1.623–5.401) and severe sarcopenia (OR 2.241, 95% CI 1.151–4.362), as well as low muscle mass (OR 2.141, 95% CI 1.219–3.760), low muscle strength (OR 7.665, 95% CI 3.438–17.091), and low physical performance (OR 2.570, 95% CI 1.401–4.716).

Conclusions

These results suggest that malnutrition contributes to sarcopenia/severe sarcopenia in MHD patients by reducing muscle mass and strength, and physical performance.

Effects of Health-Related Behaviors and Changes on Successful Aging among Indonesian Older People

Whether changes in health behaviors can improve successful aging has not been well explored. The purpose of this study was to assess the effects of health-related behaviors and changes on successful aging in Indonesian older adults. Data were from the fourth and fifth waves of the Indonesia Family Life Survey (IFLS), the participants were aged 60 years and older and who completed both waves (n = 1289). Successful aging indicators were defined as no chronic diseases, no physical function difficulties, no depressive symptoms, intact cognitive function, with social support, and with social participation. Health-related behaviors focused on smoking, physical activities, and protein intake. A logistic regression analysis was conducted. The overall successful aging rate in 2007 was 23.6%, and it had decreased to 5.6% by 2014. There were gender differences in smoking, physical activities, and behavioral changes, including promoting increased physical activity, no smoking/smoking cessation, and adequate protein intake by older adults. Quitting smoking, performing medium physical activity, and increasing protein intake were protective factors for successful aging, but the effects of behavioral changes differed by gender. Health-related behaviors and changes may impact successful aging among older adults. A healthy lifestyle is suggested to be adopted as early as possible in one's life course.

Role of muscle-targeted nutritional therapy: new data

PURPOSE OF REVIEW

To provide an updated overview of recent efficacy data on the use of muscle-targeted nutritional therapy, which should consider the optimization of protein and essential amino acids intakes, possibly in combination with supplementation with vitamin D (correction of deficiency/insufficiency status) and v-3 fatty acids.

RECENT FINDINGS

Intervention studies conducted in the last years in different healthcare settings and heterogeneous patient populations support the use of muscle-targeted oral nutritional supplementation to improve muscle mass, function and physical performance in patients with sarcopenia. Higher efficacy is likely to be achieved in combination with individually tailored resistance exercise training programs and when nutritional therapy and the provision of specific nutrients result in an adequate protein-calorie balance. However, not only a reactive but also a pro-active application of this therapy could be proposed as evidence exists on the maintenance of or improvement in the same outcome variables in patients at risk of losing skeletal muscle mass.

SUMMARY

Based on available efficacy data, both a reactive and pro-active use of muscle-targeted nutritional therapy are promising and should be proposed. However, future research should be directed toward the management of patient populations characterized by substantial muscle wasting, as these have been frequently excluded from previous trials, perhaps to avoid confounding.

Association between total protein intake and low muscle mass in Korean adults

Background

Adults with low muscle mass have a poor prognosis. Studies that examined the association between total protein intake and low muscle mass among adults are limited. Thus, we investigated the association between total protein intake and low muscle mass among Korean adults aged ≥19 years.

Methods

We included 15,995 adults (6528 male and 9467 female) aged ≥19 years from the Korea National Health and Nutrition Examination Surveys (2008–2011). We divided the participants into groups according to protein intake quartile: Q1, Q2, Q3 and Q4 groups. The odds ratios (ORs) and 95% confidence intervals (CIs) of low muscle mass according to protein intake were analysed via multivariable logistic regression analysis. Stratified analyses according to sex, age and comorbidities were also performed.

Results

Of the participants, 3.8% had weight-adjusted low muscle mass. The prevalence rates of low muscle mass were 1.5, 3.0, 3.9 and 7.2% in the Q4, Q3, Q2 and Q1 groups, respectively (p < 0.001). Compared with the Q4 group, the Q1 group had the highest ORs for low muscle mass, followed by the Q2 and Q3 groups (Model 5; OR, 95% CI: 2.03, 1.36–3.02 for Q3; 2.44, 1.64–3.61 for Q2; and 4.32, 2.89–6.45 for Q4) after adjusting for confounding variables (p for trend < 0.001). The associations between protein intake and low muscle mass were stronger in younger individuals, men, individuals without hypertension, those with diabetes mellitus and those without dyslipidemia.

Conclusions

The prevalence of low muscle mass in Korean adults significantly increased with lower protein intake. Nutrition education for proper protein intake is also important for adults.

Trial registration

Retrospectively registered.

Increases in protein intake, protein distribution score, and micronutrient intakes in older adults in response to a whole food-based dietary intervention

BACKGROUND

Changes in nutrient intakes and protein distribution were analyzed in response to a whole food-based dietary intervention targeting high-protein meals in older adults.

METHODS

Community-dwelling older adults (n = 56; M/F, 28/28; age, 69.3 ± 4.0 years) completed a 12-week intervention after randomization to exercise only (EX, n = 19), nutrition only (NUTR, n = 16), or nutrition plus exercise (NUTR + EX, n = 21). NUTR and NUTR + EX followed a dietary intervention targeting ~ 0.4 g/kg of protein at each of breakfast, lunch and dinner.

RESULTS

Relative protein intake increased in NUTR (0.99 ± 0.34 to 1.43 ± 0.39 g/kg, P < 0.001) and NUTR + EX (0.90 ± 0.20 to 1.57 ± 0.49 g/kg, P < 0.001). Intakes of cholesterol, B vitamins, selenium and iodine were increased in both NUTR and NUTR + EX (P < 0.05 for all).

CONCLUSION

This dietary intervention was effective at increasing daily protein intake and achieving an even distribution pattern. Changes in micronutrient intake were marked, and reflect the increase in consumption of animal-derived protein-rich food sources.

Diet Quality and Measures of Sarcopenia in Developing Economies: A Systematic Review

Sarcopenia refers to common age-related changes characterised by loss of muscle mass, strength, and physical performance that results in physical disability, poorer health status, and higher mortality in older adults. Diet quality is indicated as a potentially modifiable risk factor for sarcopenia. However, the association between diet quality and sarcopenia in developing economies appears to be conflicting. Hence, we conducted a systematic review of the literature from developing economies examining the relationship between diet quality and at least one of the three components of sarcopenia, including muscle mass, muscle strength, and physical performance, and the overall risk of sarcopenia. No restrictions on age and study design were employed. We identified 15 studies that met review inclusion criteria. There was heterogeneity among the studies in the diet quality metric used and sarcopenia-related outcomes evaluated. Longitudinal evidence and studies relating diet quality to a holistic definition of sarcopenia were lacking. Although limited and predominantly cross-sectional, the evidence consistently showed that diet quality defined by diversity and nutrient adequacy was positively associated with sarcopenia components, such as muscle mass, muscle strength, and physical performance.

A pas de deux of osteoporosis and sarcopenia: osteosarcopenia

The musculoskeletal conditions osteoporosis and sarcopenia are highly prevalent in older adults. Osteoporosis is characterized by low bone mass and microarchitectural deterioration of bone, whereas sarcopenia is identified by the loss of muscle strength, function and mass. Osteoporosis represents a major health problem contributing to millions of fractures worldwide on an annual basis, whereas sarcopenia is associated with a range of adverse physical and metabolic outcomes. They both affect physical and social function, confidence and quality of life as well as contributing to high health-care costs worldwide. Osteosarcopenia is the term given when both conditions occur concomitantly and it has been suggested that interactions between these two conditions may accelerate individual disease progression as co-existence of osteoporosis and sarcopenia is associated with higher morbidity from falls, fracture, disability as well as mortality. In this review, we will outline the epidemiology, pathogenesis and clinical consequences of osteosarcopenia and discuss available management strategies.

Low awareness of community-dwelling older adults on the importance of dietary protein: new insights from four qualitative studies

Meeting the recommended daily protein intake can be a challenge for community-dwelling older adults (CDOA). In order to understand why, we studied attitudes towards protein-rich products and healthy eating in general; identified needs and preferences, barriers and promotors and knowledge regarding dietary behaviour and implementation of high protein products. Attitudes towards protein-rich products and healthy eating were evaluated in focus groups (study 1, n 17). To gain insights in the needs and preferences of older adults with regard to meals and meal products (study 2, n 30), visual information on eating behaviour was assessed using photovoicing and verified in post-photovoice interviews. In studies 3 and 4, semi-structured interviews were conducted to identify protein consumption-related barriers, opportunities (n 20) and knowledge and communication channels (n 40), respectively. Risk of low protein intake was assessed using ProteinScreener55+ (Pro55+) in studies 2–4 (n 90). Focus groups showed that participants were unaware of potential inadequate dietary protein. Photovoicing showed that sixteen of thirty participants mainly consumed traditional Dutch products. In post-photovoice interviews, participants indicated that they were satisfied with their current eating behaviour. Barriers for adequate use of protein-rich products were ‘lack of knowledge’, ‘resistance to change habits’ and ‘no urge to receive dietary advice’. Promotors were ‘trust in professionals’ and ‘product offers’. Sixty-two percent had a low risk of low protein intake. CDOA feel low urgency to increase protein intake, possibly linked to low knowledge levels. A challenge for professionals would be to motivate older adults to change their eating pattern, to optimise protein intake.

Older American Women May Especially Benefit from Distributing and Consuming Protein for Decreasing Odds of Functional Limitations

OBJECTIVES

Protein is a key macronutrient for preserving physical function, but the role of protein intake on functional status may differ in men and women. We sought to examine the associations of daily protein intake and distribution on functional limitations in older American men and women.

DESIGN

Cross-sectional.

SETTING

Population-based survey.

PARTICIPANTS

The analytic sample included 3,976 men and 4,081 women aged ≥60-years from the 2007-2016 waves of the National Health and Nutrition Examination Survey.

MEASUREMENTS

Participants reported their ability to perform basic activities of daily living, instrumental activities of daily living, leisure and social activities, lower extremity mobility activities, and general physical tasks. Those reporting difficulty or an inability in completing such functional tasks were considered as having a functional limitation. Protein intake was determined with dietary recalls and participants revealed functional limitations. Protein recommendations of ≥0.80, ≥1.00, and ≥1.50 g/kg/day were used. Based on these cut-points, we also investigated distribution of protein across 4 eating occasions at ≥0.20, ≥0.25, and ≥0.38 g/kg/meal, respectively.

RESULTS

Older women meeting each recommendation had decreased odds for functional limitations: 0.55 (95% confidence interval (CI): 0.40-0.75) for ≥0.80 g/kg/day, 0.75 (CI: 0.58-0.97) for ≥1.00 g/kg/day, and 0.72 (CI: 0.55-0.94) for ≥1.5 g/kg/day. No significant associations were observed in older men. Further, older women with protein consumption ≥0.20 g/kg/meal had decreased odds for functional limitations: 0.24 (CI: 0.10-0.61) for 1 occasion, 0.20 (CI: 0.08-0.49) for 2 occasions, 0.16 (CI: 0.07-0.40) for 3 occasions, and 0.12 (CI: 0.04-0.32) for 4 occasions. A similar trend was observed for intake ≥0.25 g/kg/meal: 0.31 (CI: 0.16-0.62) for 2 occasions, 0.30 (CI: 0.14-0.61) for 3 occasions, and 0.31 (CI: 0.12-0.78) for 4 occasions. Women with 1 and 2 eating occasions at ≥0.38 g/kg/meal of protein had 0.66 (CI: 0.48-0.91) and 0.54 (CI: 0.37-0.79) decreased odds for functional limitations, respectively.

CONCLUSION

Trials that are powered to detect the effects of protein on functional status in women will help to establish causality.

Optimising an intervention to support home-living older adults at risk of malnutrition: a qualitative study

Background

In the UK, about 14% of community-dwelling adults aged 65 and over are estimated to be at risk of malnutrition. Screening older adults in primary care and treating those at risk may help to reduce malnutrition risk, reduce the resulting need for healthcare use and improve quality of life. Interventions are needed to raise older adults’ risk awareness, offer relevant and meaningful strategies to address risk and support general practices to deliver treatment and support.

Methods

Using the Person-based Approach and input from Patient and Public Involvement representatives, we developed the ‘Eat well, feel well, stay well’ intervention. The intervention was optimised using qualitative data from think aloud and semi-structured process evaluation interviews with 23 and 18 older adults respectively. Positive and negative comments were extracted to inform rapid iterative modifications to support engagement with the intervention. Data were then analysed thematically and final adjustments made, to optimise the meaningfulness of the intervention for the target population.

Results

Participants’ comments were generally positive. This paper focuses predominantly on participants’ negative reactions, to illustrate the changes needed to ensure that intervention materials were optimally relevant and meaningful to older adults. Key factors that undermined engagement included: resistance to the recommended nutritional intake among those with reduced appetite or eating difficulties, particularly frequent eating and high energy options; reluctance to gain weight; and a perception that advice did not align with participants’ specific personal preferences and eating difficulties. We addressed these issues by adjusting the communication of eating goals to be more closely aligned with older adults’ beliefs about good nutrition, and acceptable and feasible eating patterns. We also adjusted the suggested tips and strategies to fit better with older adults’ everyday activities, values and beliefs.

Conclusions

Using iterative qualitative methods facilitated the identification of key behavioural and contextual elements that supported engagement, and issues that undermined older adults’ engagement with intervention content. This informed crucial revisions to the intervention content that enabled us to maximise the meaningfulness, relevance and feasibility of the key messages and suggested strategies to address malnutrition risk, and therefore optimise engagement with the intervention and the behavioural advice it provided.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01572-z.

Protein Knowledge of Older Adults and Identification of Subgroups with Poor Knowledge

The aim was to investigate the protein knowledge of community-dwelling older adults. A survey was conducted among 1825 adults aged ≥65 years and living in Finland, Netherlands, Poland, Spain and United Kingdom in 2017. Protein knowledge was measured with nine objective knowledge statements provided only to participants who indicated to know what the nutrient "protein" is (64.7% of sample). Demographic, socioeconomic and health determinants of poor protein knowledge were investigated using multiple logistic regression analyses. The sample was 49.6% female and 87.0% reported no walking difficulties. Participants scored best on the true statement "You need protein in the diet for repairing bones and muscles" (89.3% correct), and worst on the false statement "One meal per day with a good protein source is sufficient" (25.4% correct). Median knowledge score was 5.0 (scale 0–9) and poor knowledge was present in 49.4% of the sample. Males (Odds Ratio 1.57), those unable to walk for 5 min (2.66), not always making their own food decision (1.36) and having lower income (1.44) were more likely to have poor knowledge. Large differences were observed across countries. In conclusion, poor protein knowledge is present in about half of community-dwelling older adults. Communication strategies should be tailored to target the identified risk groups with poor knowledge.