Design and evaluation of a nutritionally adequate diet for healthy ageing in older UK adults: The Healthy Ageing DIet (HADI) Study

英国人口正在迅速老龄化。到2025年，65岁的成年人数量将翻一番，达到1850万，其中增长最快的85岁1。一项关键的公共卫生挑战是确定有效的解决办法，以减少残疾和发病率，并延长英国公民的健康范围2。在这方面，充足的营养可以防止与年龄相关的身体和认知功能下降3，4，并预防慢性疾病，如心血管疾病5。《伊特韦尔指南》提供了提供所需参考营养素摄入量(RNI)的食物类别的建议，并以较低的环境影响促进整体英国人口健康6。然而，衰老与许多生理变化有关，例如嗅觉功能和味觉丧失7、炎症和免疫反应改变8、身体成分改变9、胃排空延迟10扰乱食欲调节11、导致食物偏好改变12和营养生物利用率降低13使老年人易患营养缺乏14。Lovegrove等人最近报告了强有力的证据，支持在英国65岁的老年人中蛋白质、钙、叶酸和B12的RNI增加。因此，老年人的营养需求与年轻人不同，英国的饮食指南还没有充分考虑到这一点。老龄化期间令人关注的其他营养素包括钾、铁、锌、维生素A、维生素C、维生素E、维生素K、维生素B6和维生素D13的摄入量不足，以及饱和脂肪、糖和钠过量15。迫切需要为晚年的最佳健康和福祉定义营养充足的饮食建议，并提供有针对性的农业食品创新，以帮助65岁的英国公民满足他们的营养需求。拟议的博士项目旨在通过以下方式解决这些差距：(I)结合证据审查、最先进的饮食建模技术和利益相关者参与，为英国老年人设计健康老龄化饮食(HADI)；以及(Ii)评估HADI对营养摄入量、营养状况和健康老龄化措施的影响。研究问题1.什么是实现老年人营养充足所需的最佳食物组合，以及在与英国当前饮食最小偏差的情况下实施的可行性？我们假设，定义可接受的食物组合以最佳地满足英国老年人的营养需求是可行的。在英国老年人中，坚持优化的健康老龄化饮食(HADI)与营养状况之间有什么联系？我们假设，HADI将与关注的关键营养素的充足摄入量和状态有关3.优化的HADI与身体和认知表现的变化以及慢性病风险有何关系？我们假设，更多地坚持HADI将与减缓认知和功能衰退以及降低心血管疾病的风险相关。主要目标是：1.完成对老年人营养不良对健康影响的系统评估(1岁)2.使用国家食品消费数据应用饮食优化模型来定义Eatwell指南中表示的食物组比例的最低饮食变化量，以满足65岁成年人的营养需求(1-2岁)3.使用这些模型来确定需要强化饮食以满足老年人营养需求的“问题”营养物质(2岁)4.与老年消费者进行定性研究和农业食品行业利益相关者定义可接受的食品，以进行有针对性的营养强化和产品创新(第2年)5.构建HADI评分以确定65年来(第3年)对优化健康饮食的坚持6.在具有全国代表性的英国老龄化队列中进行纵向数据分析，以确定HADI、营养状况与健康老龄化(3-4年级)

The UK population is ageing rapidly. By 2025, the number of adults aged 65 years will double to reach 18.5 million, with fastest growth expected among those 85 years1. A key public health challenge is to identify effective solutions to reduce disability and morbidity and extend the health span of UK citizens2. In this regard, adequate nutrition can protect against age-related physical and cognitive function decline3,4 and prevent chronic disease such as cardiovascular disease5. The Eatwell Guide provides advice on food groups which supply the required reference nutrient intake (RNI) and promote overall UK population health with low environmental impacts6. However, ageing is associated with numerous physiological changes e.g. loss of olfactory function and taste7, altered inflammatory and immune responses8, altered body composition9, delayed gastric emptying10 disrupted appetite regulation11, leading to altered food preferences12 and decreased nutrient bioavailability13 that predispose older adults to nutrient deficiency14. Lovegrove et al14, recently reported strong evidence to support an increased RNI for protein, calcium, folate and B12 among those aged 65 years in the UK. Hence, older adults have nutritional needs that differ from those of the younger adults and which have not yet been fully considered in UK dietary guidelines. Other nutrients of concern during ageing include suboptimal intakes of potassium, iron, zinc, vitamin A, vitamin C, vitamin E, vitamin K, vitamin B6 and vitamin D13 and excess saturated fat, sugar and sodium15. There is a critical need to define nutritionally adequate dietary recommendations for optimal health and well-being in later life and inform targeted agri-food innovations to help UK citizens aged 65 years meet their nutritional needs. The proposed PhD project aims to address these gaps by: (i) combining evidence review, state of the art diet modelling techniques and stakeholder engagement to design a Healthy Ageing DIet (HADI) for older UK adults; and, (ii) evaluating the impact of HADI on nutritional intake, nutritional status and measures of healthy ageing. Research questions1. What are the optimal food combinations required to achieve nutritional adequacy in older adults and feasible to implement with minimal deviation from the current UK diet? We hypothesise that it is feasible to define acceptable food combinations to optimally meet the nutritional needs of older UK adults2. What is the association between adherence to an optimised Healthy Ageing DIet (HADI) and nutritional status in older UK adults? We hypothesise that HADI will be associated with adequate intake and status of key nutrients of concern 3. How does an optimised HADI relate to changes in physical and cognitive performance and chronic disease risk? We hypothesise that greater HADI adherence will be associated with slower cognitive and functional decline and reduced risk of cardiovascular disease Main objectives are to:1. Complete a systematic review on health impact of undernutrition in older adults (year 1)2. Apply diet optimisation modelling using national food consumption data to define the minimum amount of dietary change to food group proportions represented in the Eatwell Guide to meet nutritional requirements for adults 65 years (year 1-2)3. Use the models to determine 'problem' nutrients requiring diet fortification to meet the nutritional needs of older adults (year 2)4. Conduct qualitative research with older consumers and agri-food industry stakeholders to define acceptable foods that would be feasible for targeted nutrient fortification and product innovation (year 2)5. Construct HADI score to determine adherence to an optimised healthy diet for 65 years (year 3)6. Conduct longitudinal data analysis in nationally representative UK ageing cohorts to determine relations between HADI, nutritional status and healthy ageing (year 3-4)