Proceedings of the Nutrition Society最新文献

Healthy diets are unaffordable for billions of people worldwide, with food prices rising in high-, middle- and low-income nations in recent times. Despite widespread attention to this issue, recent actions taken to inform policy prioritisation and government responses to high food inflation have not been comprehensively synthesised. Our review summarises (i) innovative efforts to monitor national food and healthy diet price, ii) new policy responses adopted by governments to address food inflation and (iii) future research directions to inform new evidence. Evidence synthesis. Global. None. We describe how timely food and beverage pricing data can provide transparency in the food industry and identify key areas for intervention. However, government policies that improve food affordability are often short-lived and lack sustained commitment. Achieving meaningful impact will require long-term, cross-sectoral actions that are led by governments to support food security, healthy diets and resilient sustainable food systems. This will necessitate a better understanding of how the political economy enables (or hinders) policy implementation, including through coherent problem framing, mitigating conflicts of interest in policymaking, working together as coalitions and developing and utilising evidence on the food security and related impacts of food pricing and affordability policies. Diverse actors must be better equipped with robust data platforms and actionable policy solutions that improve the affordability of healthy and sustainable diets, including by lowering food prices and addressing the broader socio-political determinants of food insecurity.

Unhealthy diets are a leading cause of preventable ill health. Healthy diets tend to be more expensive than less healthy diets and as such are more likely to be consumed by individuals with a higher income. This review paper discusses the development of the Eatwell Guide, evaluates the affordability of a diet consistent with the Eatwell Guide ('the Eatwell Guide diet') and explores how food pricing can be leveraged to encourage and support healthier dietary choices. The Eatwell Guide is the UK's food-based dietary guidelines. It provides healthy eating advice that is intended to facilitate policy cohesion but is also used as a public-facing health promotion tool. The cost of food has increased and recent estimates suggest that the Eatwell Guide diet is now more expensive than the current average diet. There is strong evidence that subsidies would be effective at increasing the uptake of healthy diets. Monitoring the cost of a healthy diet is important for policy development; however, we should exercise caution when considering how to incorporate costs into food-based dietary guidelines and be mindful of the limitations of the data that could support this.

(Poly)phenols are plant secondary metabolites widely abundant in plant foods and beverages comprising a very large number of compounds with diverse structure and biological activities. Accumulating evidence indicates that these compounds exert beneficial effects against cardiometabolic diseases, and this review will provide a summary of current knowledge in this area. Epidemiological and clinical data collectively suggest that intake of flavonoids reduces the risk of cardiovascular disease (CVD), with the evidence being particularly strong for the flavan-3-ol subclass. However, to provide adequate dietary recommendations, a better understanding of their estimated content in foods and intake among the general public is needed. Regarding mechanisms of action, we now know that it is unlikely that (poly)phenols act as direct antioxidants in vivo, as it was hypothesised for decades with the popularity of in vitro antioxidant capacity assays. One of the reasons is that upon ingestion, (poly)phenols are extensively metabolised into a wide array of circulating metabolites with different bioactivities than their precursors. Well-conducted in vitro and in vivo studies and human nutrigenomic analysis have revealed new molecular targets that may be underlying the health benefits of (poly)phenols, such as the nitric oxide pathway. Recently, a bi-directional relationship was established between (poly)phenols and the gut microbiota, suggesting that individual gut microbial metabolising capacity may be a key factor explaining the variability in the cardiometabolic response to (poly)phenols. Future research is needed to elucidate which are the key factors affecting such capacity, and whether it can be modulated, along with the mechanisms of action.

School food has a major influence on children's diet quality and has the potential to reduce diet inequalities and non-communicable disease risk. Funded by the UK Prevention Research Partnership, we have established a UK school food system network. The overarching aim was to build a community to work towards a more health-promoting food and nutrition system in UK schools. The network has brought together a team from a range of disciplines, while the inclusion of non-academic users and other stakeholders, such as pupils and parents, has allowed the co-development of research priorities and questions. This network has used a combination of workshops, working groups and pump-priming projects to explore the school food system, as well as creating a systems map of the UK school food system and conducting network analysis of the newly established network. Through understanding the current food system and building network expertise, we hope to advance research and policy around food in schools. Further funding has been achieved based on these findings, working in partnership with policymakers and schools, while a Nutrition Society Special Interest Group has been established to ensure maximum engagement and future sustainability of the network. This review will describe the key findings and progress to date based on the work of the network, as well as a summary of the current literature, identification of knowledge gaps and areas of debate, according to key elements of the school food system.

This review aims to critically evaluate the efficacy of long-chain ո-3 PUFA ingestion in modulating muscle protein synthesis (MPS), with application to maintaining skeletal muscle mass, strength and function into later life. Ageing is associated with a gradual decline in muscle mass, specifically atrophy of type II fibres, that is exacerbated by periods of (in)voluntary muscle disuse. At the metabolic level, in otherwise healthy older adults, muscle atrophy is underpinned by anabolic resistance which describes the impaired MPS response to non-pharmacological anabolic stimuli, namely, physical activity/exercise and amino acid provision. Accumulating evidence implicates a mechanistic role for n-3 PUFA in upregulating MPS under stimulated conditions (post-prandial state or following exercise) via incorporation of EPA and DHA into the skeletal muscle phospholipid membrane. In some instances, these changes in MPS with chronic ո-3 PUFA ingestion have translated into clinically relevant improvements in muscle mass, strength and function; an observation evidently more prevalent in healthy older women than men. This apparent sexual dimorphism in the adaptive response of skeletal muscle metabolism to EPA and DHA ingestion may be related to a greater propensity for females to incorporate ո-3 PUFA into human tissue and/or the larger dose of ingested ո-3 PUFA when expressed relative to body mass or lean body mass. Future experimental studies are warranted to characterise the optimal dosing and duration of ո-3 PUFA ingestion to prescribe tailored recommendations regarding n-3 PUFA nutrition for healthy musculoskeletal ageing into later life.

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

Food systems in Africa are under pressure from climate change, conflicts, health pandemics such as COVID-19 and rising food prices. The COVID-19 pandemic highlighted weaknesses in global food systems and indeed Africa's was not spared. Although COVID-19 mortality and morbidity in Africa were relatively low in comparison to other regions, the containment measures employed by countries amplified a rather dire situation. Disruptions were seen in livelihoods, food value chains, increases in food prices and loss of income. These changes affected access to nutritious foods. A resilient food system that can withstand and recover from disruption and shocks will be important for ensuring access to healthy diets for all. This review paper assesses the state of food insecurity and malnutrition situation pre-COVID-19 and the impact of COVID-19 on Africa's food systems and access to healthy diet. To put Africa on a path to accelerated recovery, a resilient and sustainable food system will be crucial. The following recommendations are made: (i) increasing agriculture productivity, with special attention to the foods that contribute to healthy diets - fruits and vegetables, and animal source foods (ii) promoting the production and consumption of nutritious African traditional and indigenous foods (iii) transforming Africa's food systems to be gender-sensitive (iv) investing in well-targeted social protection programmes (v) supporting food environments that protect healthy diets and (vi) employing data and information to monitor food systems transformation.

The relationship between nutrition and ageing is complex. The metabolism and synthesis of micronutrients within the gut microbiome can influence human health but is challenging to study. Furthermore, studying ageing in humans is time-consuming and difficult to control for environmental factors. Studies in model organisms can guide research efforts in this area. This review describes how the nematode Caenorhabditis elegans can be used to study how bacteria and diet influence ageing and inform follow-on studies in humans. It is known that certain bacteria accelerate ageing in C. elegans. This age-accelerating effect is prevented by inhibiting folate synthesis within the bacteria, and we propose that in the human microbiome, certain bacteria also accelerate ageing in a way that can be modulated by interfering with bacterial folate synthesis. Bacterial-derived folates do not promote ageing themselves; rather, ageing is accelerated by bacteria in some way, either through secondary metabolites or other bacterial activity, which is dependent on bacterial folate synthesis. In humans, it may be possible to inhibit bacterial folate synthesis in the human gut while maintaining healthy folate status in the body via food and supplementation. The supplement form of folic acid has a common breakdown product that can be used by bacteria to increase folate synthesis. Thus, supplementation with folic acid may not be good for health in certain circumstances such as in older people or those with an excess of proteobacteria in their microbiome. For these groups, alternative supplement strategies may be a safer way to ensure adequate folate levels.

It is estimated that more than one-tenth of adults aged ≥60 years are now classified as having sarcopenic obesity (SO), a clinical condition characterised by the concurrent presence of sarcopenia (low muscle mass and weakness) and obesity (excessive fat mass). Independently, sarcopenia and obesity are associated with a high risk of numerous adverse health outcomes including CVD and neurological conditions (e.g. dementia), but SO may confer a greater risk, exceeding either condition alone. This imposes a substantial burden on individuals, healthcare systems and society. In recent years, an increasing number of observational studies have explored the association between SO and the risk of CVD; however, results are mixed. Moreover, the pathophysiology of SO is governed by a complex interplay of multiple mechanisms including insulin resistance, inflammation, oxidative stress, hormonal shifts and alteration of energy balance, which may also play a role in the occurrence of various CVD. Yet, the exact mechanisms underlying the pathological connection between these two complex conditions remain largely unexplored. The aim of this review is to examine the association between SO and CVD. Specifically, we seek to: (1) discuss the definition, epidemiology and diagnosis of SO; (2) reconcile previously inconsistent findings by synthesising evidence from longitudinal studies on the epidemiological link between SO and CVD and (3) discuss critical mechanisms that may elucidate the complex and potentially bidirectional relationships between SO and CVD.

Globally, we are currently facing a rapid demographic shift leading to an increase in the proportion of older adults within the population. This raises concerns about the potential increase in age-related diseases and their impact on our ability to provide adequate health and end-of-life care. To apply appropriate interventions, understanding the changes that happen with ageing becomes essential. Ageing is often accompanied by a decrease in appetite and physical activity, which may lead to malnutrition, resulting in decreased muscle mass, physical capabilities and independence. To preserve muscle mass, older adults are advised to increase protein intake and physical activity. However, protein's high satiating effect may cause reduced energy intake. Physical activity is also advised to maintain or enhance older adult's appetite. This review paper aims to discuss appetite-related changes that occur with ageing and their consequences. In particular, it will focus on investigating the relationship between protein intake and physical activity and their impact on appetite and energy intake in the ageing population. Recent studies suggest that physical activity might contribute to maintaining or enhancing appetite in older adults. Nevertheless, establishing a definitive consensus on the satiating effect of protein in ageing remains a work in progress, despite some promising results in the existing literature.