Malnutrition in older adults in the UK

Healthy eating guidance for the general population in the UK is encapsulated in the Eatwell Guide [1]. However, this guidance is not considered by some to be sufficiently specific to be applied to older adults due to changes in nutritional requirements as a result of ageing [2]. The focus on the health of older adults is now more relevant due to population ageing across the world [3] as well as in the UK [4]. In England and Wales, the number of older adults (aged 65 and above) has increased from 9.2 million (16.4% of the population) in 2011, to 11 million (18.6% of the population) in 2021 [4]. Globally by 2050, 1 in 6 of the population will be aged 60 and above [3].

Although energy requirements in older adults are often lower compared to the general adult population due to changes in body composition, requirements for vitamins and minerals remain the same apart from iron which has a lower reference nutrient intake [5 p29]. Additionally, recommendations for protein intake may increase for older adults to prevent sarcopenia [6]. The consumption of a healthy and nutrient dense diet is important in older adults to ensure healthy ageing [2,3,7]. Physiological and psychological factors commonly associated with ageing such as loss of taste and smell, depression and social isolation may result in loss of appetite [8] impacting on the ability of older adults to meet their nutritional requirements which can then result in the development of malnutrition [9].

Malnutrition is normally defined through a two-stage approach initially using a validated risk tool followed by a phenotypic assessment (weight loss, low BMI) and aetiologic assessment (loss of appetite, feeling weak or tired, increased incidence of episodes of illness) [10]. Before the Covid-19 pandemic the number of older adults living in the community in the UK with malnutrition or undernutrition was estimated to range from between 5 and 10% [11,12], affecting over 1.3 million adults in the UK alone. As well as impacting quality of life in this demographic, this has a significant socioeconomic burden.

Malnutrition was estimated to cost the UK £23.8 billion in 2017 [13,14]. Current societal challenges including the cost-of-living crisis mean that the number of adults living with malnutrition is likely to have increased [15]. Data from the Health Survey for England show that 79% of adults aged 65–74 years and 69% aged 75 years and over are overweight or living with obesity [16].

Concerted effort is needed to address malnutrition in older adults in order to address this public health crisis. Malnutrition is of global concern and part of the wider public health agenda where there is a focus on ending hunger and ensuring healthy lives for all ages [17]. While there has been a reduction in hunger and mortality rates since 2015, the gains in these areas have declined since the pandemic [18]. In the UK, 1 in 10 aged 60 and above (1.4 million) have been finding it more difficult to access healthy food since the pandemic [19] and almost half of those screened for malnutrition have been found to be malnourished [20]. There is a UK public health focus on addressing malnutrition [21] requiring actions to prevent, recognize and manage malnutrition once identified [8]. Research suggests that older adults have a low awareness of malnutrition and so part of the effort to address malnutrition with older adults include nutritional awareness [22]. There is a need for nutritional education and/or interventions focused on increasing the nutrient density of foods chosen by groups of the older population, including those who are malnourished and/or frail. In order to support nutrition strategies to ensure healthy ageing, there is a need to understand the information practice of older adults [23]. That is, where they source nutrition information, how they understand and respond to information, and how this information can be used to support adults to make the dietary changes necessary to meet changing nutritional needs.

Nutrition education resources used by older adults

Health information practice is a key component enabling self-management to maintain health [23], however the process of information practice and information gathering is instinctive and taken for granted [24]. Although, people are exposed to a range of sources of nutritional information, including media sources (TV, radio, newspapers etc), the internet, as well as labels on food packaging [25]. Nutrition information is also gained through individual daily practices [26,27] leading to hidden tacit knowledge that is embodied [28]. However, we know very little about where older adults source nutritional information, or how this informs what they choose to eat. While current front of pack food labels is offered as a source of nutrition information for older adults [29], the population-based approach of providing advice from statutory sources, often focusing on addressing obesity, can impact negatively on those who are nutritionally vulnerable [29].

Nutritional labelling in the UK should comply with regulations set by Government [30] however the current traffic light system is voluntary [31]. The aim of nutrition food labelling is to ‘ensure that consumers understand what they are buying and that “it is what it says it is”’ [32]. Although food labels have been found to be one of the main sources of nutrition information used by the public [33], the use of food labels by older adults is low [29,33]. Research suggests this group may have difficulties in interpreting the information [29,33,34] making food labels potentially ineffective in facilitating food choices and potentially leading to a worsening nutritional intake. There is anecdotal evidence that there may be unintended consequences of the “one-size fits-all” approach to nutritional labelling [26] by those working with older adults. The quote below identifies the concern about the inappropriate focus on foods labelled red (high) amongst older adults resulting in weight loss and subsequently malnutrition:

‘Many of the people attending our services worry about eating things that may be ‘bad’ for them, such as those marked with a danger-invoking, red traffic lights. Sadly, many of these people join our service having lost weight unintentionally, and at risk of, or already malnourished.’ (Sarah Wren, Chief Executive of Health and Independent Living Support (HILS) - a social enterprise that supports older people with meals on wheels, nutritional advice, and wider health and wellbeing services.)

Maintaining a nutritious, balanced and enjoyable diet plays a crucial role in ageing healthily and avoiding conditions that arise from malnutrition [2]. As the world’s population continues to age, understanding what barriers older adults face in accessing healthy meals requires more focus. A systematic review undertaken by Host et al. [35] identified that there are a range of factors influencing nutritional intake in older adults. While Brownie [36] found that information about what to eat has a key influence on food practices, the impact of being on the receiving end of nutritional campaigns over a longer period of time may make decisions about what to eat more challenging.

Recognizing what messages concerning a healthy diet are being received by older adults through their information practice [23] and where older adults find such information in the first place might give us an insight into how decisions about food are being made by this population group.

Although there is research exploring sources of health information in healthy older adults [37] and in those with long term conditions [38] as well as sources of nutrition information in the general public (for example [39]), there appears to be limited research exploring sources of nutrition information and their impact on food decisions in older adults. There is no one solution to reducing malnutrition among older adults, however, influencing adults’ eating habits through provision of nutritional information is worthy of exploration. Obtaining accurate and suitable nutrition information is fundamental to informing healthier dietary choices, positive nutrition attitudes, and optimizing nutritional status.

This study formed the first phase of a two-stage project entitled: “Exploring sources of nutritional information used by older people: A feasibility study”. The second phase involved the development of a nutrition information diary [details available in S1 File: Food4years conference]. The project team was supported by an advisory group including members from the community working with older adults and members of the University’s Public Involvement Research Group (PIRg) [40]. Bimonthly meetings were held to monitor progress and to ensure that the project reflected community needs of older adults and lay views and opinions. Although the UK uses the age of 65 when referring to older adults [4], we have used the age range 60 and above to refer to older adults. Early in the research process we found that there was limited research on the topic of nutrition information in older adults in the UK. Therefore, the focus of the search included studies undertaken outside the UK where many used the age of 60 and over to define older adults, a definition also used by the WHO [3].

Aim

This study aims to explore sources of information free living older adults draw on to inform their food choices and understanding of a healthy diet using health information practice as the conceptual framework.

Criteria for inclusion and search strategy

Inclusion criteria are summarized in Fig 2. To be eligible for inclusion, studies had to include older adults aged over 60 years. Where studies included a range of participants across age ranges, data needed to be reported separately for participants over 60. The review focused on free living older adults and does not include studies which focus solely on older adults living in care homes, or those with particular diseases or long-term medical conditions as the findings would not be generalizable to the wider population [48]. Participants had to have been exposed to or impacted by at least one source of nutrition information. Eligible papers report outcomes referring to a change in food habits or preferences or a change in the understanding, perception or awareness of nutrition information. Papers were excluded if they focused on younger adults alone, did not relate to sources of nutrition information among older adults; were reviews, a letter to the editor, conference abstract; or if no full text was available. In order that the review reflected current issues, papers were excluded if they were published before 2000. Studies written in languages other than English were excluded.

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Fig 2. Inclusion and exclusion criteria and search terms.

https://doi.org/10.1371/journal.pone.0341015.g002

The search was conducted in March 2023 (search 1) and updated in February 2025 (search 2), across three databases: PUBMED, Scopus and CINAHL. Predefined keywords in the search strategy based on the Population, Exposure, Outcomes (PEO) framework as outlined in Fig 2 were agreed with the research team and at the public advisory group meetings. The search strategy was developed with the assistance of an information manager specialist in the Library and Computing Service at the University of Hertfordshire. The results of search 1 were downloaded into Rayyan screening software [49], duplicates removed, and two assessors (TI, EB) independently evaluated the relevancy of each paper against the inclusion/exclusion criteria (that is each paper was evaluated by each assessor). The resulting studies were then downloaded into Microsoft Excel. Due to the small number of results from search 2, these were downloaded directly into Excel, duplicates were identified and removed by hand by two members of the research team (JM,AD). As the initial search team were not available to undertake this task, two assessors (JM, AD) independently evaluated the relevancy of each paper against the inclusion/exclusion criteria. A third reviewer who was a member of the PIRg and trained in scoping reviews (JJ) was asked to settle any differences of opinion across both search 1 and search 2 to ensure consistency. Agreement was reached for all studies included in the final review.

Data charting process

Data from each study were extracted and charted into Excel by the two members of the research team who undertook the search (search 1: TI,EB, search 2: JM,AD) using headings: author, year, aims of the study, country and study setting (for example community or hospital), study design and methods, number, age and gender of participants and finally the outcome of the research and what the study adds to what is known about nutrition information sources used by older adults. Where the study was undertaken in the hospital setting, the paper was reviewed to confirm that the participants were free living. Charted data was checked by the lead author (JM). The studies were grouped into methodologies of quantitative, qualitative and mixed methods. This final synthesis was discussed with the research team and advisory group.

Characteristics of included studies

Sources of nutritional information

The studies found that a wide range of sources of nutritional information were used by older adults. The most common sources were magazines which were identified by eight studies [51,55–57,59–61,64]; family and friends (seven studies) [51,54,57,59,61,62,64] television (six studies) [54,56,57,59,61,64]; dietitians (six studies) [51,54–56,59,61]. Most studies reported on several sources of information, 4 studies reporting on a wide range of sources [58,59,61,64] and 4 studies reporting on one source. Doma et al. [50] and Mccharles and Fox [63] who reported on national food guidance, González-Contreras et al. [53] on food labels and Turner at al [65] who reported on the internet as a source of nutrition information. These are summarized in Fig 8

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Fig 8. Collation of sources of information identified by the studies.

https://doi.org/10.1371/journal.pone.0341015.g008

Outcomes of studies

In this section we explore the main themes identified through the analysis of the studies. The studies in alphabetical order are collated by main theme in Fig 9: Sources relied on and preferred; Need for information; Embodied nutritional knowledge; Impact on food practices; Gender differences; Education levels and skills; Trust and conflicting messages. The subthemes by study are listed in Fig 10.

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Fig 9. Studies in alphabetical order by main theme.

https://doi.org/10.1371/journal.pone.0341015.g009

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Fig 10. Subthemes by study.

https://doi.org/10.1371/journal.pone.0341015.g010

Sources relied on and preferred

A number of studies highlighted a wide range of preferred sources for nutritional information for older adults. Duerr [61] who used focus groups to explore information sources currently used and what learning methods were ‘liked’ by 37 participants grouped preferred sources into written mixed mediums, people, organisations, other (fairs, cooking demos, courses). Oliveira et al. [58] found preferences for a wide range of media, such as booklets with pictures, informational posters, and food education and practical cooking sessions. While participants in Ong et al. [59] reported that television (40%) and internet (40%) were the most used sources followed by printed materials such as newspapers (39.3%) books/magazines (32.3%) and word of mouth, e.g., through friends (20.3%) and family (14.3%). McKay et al. [57] also found newspapers (61.8%) as being frequently referred to alongside doctors (61,8%), followed by magazines (60.1%) and television (49.1%). However, Heuberger and Ivanitskaya [54] found that most participants preferred to receive nutritional information from health care professionals (HCPs) who were not registered dietitians and Maccharles and Fox [63] found that their participants did not feel that guidance from HCPs would be helpful.

Studies explored preferred sources of information about specific food items. Farrell et al. [51] found the most common preferred sources for bean information included food labels (54.8%) as well as brochures (51.2%) and the internet (47.2%). While Vella et al. [60] explored sources of information about functional foods with 200 older adults (70% women) through a researcher completed questionnaire and found that 68.5% preferred newspapers, magazines, and books as sources of nutritional information about functional foods.

Sources for nutrition information were selected for particular reasons. Duerr [61] found that participants chose a source as it was an effective way to learn and both Duerr [61] and Rueter et al. [64] found that enjoyment and interest on a topic influenced using a source of information. The availability of information also influenced use. Duerr [61] found that being able to take information away and read it later and both Rueter et al. [64] and Maccharles and Fox [63] found that having information available at the point of purchase in the form of a food label would be effective in guiding them whether to purchase a food or not.

The situation of participants was also found to influence preference for sources of information. Heuberger and Ivanitskaya [54] found that the presence of poor health meant they preferred advice from a dietitian whilst those in good health preferred nutritional advice from a HCP who was not specialised. Oliveira et al. [58] found those with adequate social support preferred booklets with text.

Preferences for format of the information was identified by some studies. Duerr [61] found their participants valued practical learning methods such as demonstrations, discussions, classes, eating and tasting and Oliveira et al. [58] for practical cookery sessions as well as ‘audiovisual’ or leaflets with images alongside the text. Turner et al. [65] in their participatory design workshops explored preferences for the delivery of digital nutrition information. They found that while participants made use of a range of electronic devices including SMART phones, they preferred a web site as opposed to an app for nutritional information.

Need for information

Eight studies reported on their participants’ need for nutrition information. Oliveira et al. [58] who undertook a questionnaire with 602 older adults in Portugal found that most participants were concerned about healthy eating (87.5%) and would like more information on this topic (69.3%). However, two studies found that participants would like a broad range of nutrition information. Duerr [61] in their focus group study with participants in the USA identified seven categories that their participants wanted more information about: basic nutrition, diet and disease, lifestyle, specific foods, supplements, general education. Turner et al. [65] who undertook participatory discussion groups online found that older adults would like nutritional information such as nutrient values, practical information including how to read food labels, finding seasonal healthy food, using leftovers and a source that could be personalized to their own needs as “one size does not fit all” (page 6). Duerr [61] also found the need for adapting recipes and on how to eat healthily on a fixed income. Maccharles and Fox [63] who explored the Canada Food Guide with a small group of older adults in focus groups (women n = 10, men n = 2) found their participants needed to know how to select affordable healthy food and needed more guidance on portion sizes as this was not clear. However, nutritional information was considered valuable in making food choices. Farrell et al. [51] and Vella et al. [60] who explored information needs about beans and functional foods respectively found their participants would like more nutrition information about these foods. While Rueter et al. [64] found that their participants would like information as they were interested in the topic, they did not always need nutrition information. Duerr [61] also found some of their participants did not need information, in this case it was because they had no food issues. Maccharles and Fox [63] found that not all information was considered relevant to their participants. For example, they had no need for information on processed foods as they ‘did not eat that kind of food’.

Although older adults make use of a wide range of sources to support their decision making, they do not always have food issues requiring information and information about foods that they do not normally eat are not relevant to them.

Embodied nutritional knowledge

The studies appear to indicate that the relationship between embodied nutritional knowledge (hidden and gained through individual practices [27,28]) and food chosen/eaten by older adults is not straightforward. Gustafsson and Sidenvall [62] who undertook qualitative interviews and a 3 day food diary exploring food related health perceptions and habits with 18 women in Sweden found that their participants held embodied perceptions about food and health. Their participants believed that feeling healthy meant that you must be eating healthily, and that this was enhanced by consuming home cooked meals. However, not all their views were positive; they had an embodied fear of fat which led to cooking low fat meals.

Studies found an association between nutritional knowledge and eating practices and behaviours. Vella et al. [60] found 85.5% of their participants felt that increased awareness and knowledge about functional foods would promote their consumption. Jeruska-Bielak et al. [55] found that good nutritional knowledge was associated with a healthier body mass index and physical activity and positive nutritional related attitudes (which they define as emotions, motivations, perceptions and cognitive beliefs). Farrell et al. [51] also found a link between beliefs and food behaviours, finding that participants who had a greater belief in the impact of diet on health were more likely to take notice and list use of health claims as influencing their food choices.

Conversely, studies also found that general awareness of a food or food practice does not always promote healthy food practices. Doma et al. [50] who undertook a researcher administered questionnaire with 250 older adults followed by focus groups with 10 participants found that while 98% of participants were aware that beans were a healthy food item, only 51.2% were regular consumers. Laurenti et al. [56] who undertook a self-administered questionnaire with 201 older adults (women n = 150, men n = 51) who were attending a ward-based, outpatient clinic gym session for older adults in Italy found that while most participants said they followed safe food practices, 49.4% defrosted food at room temperature and 33.8% consumed food out of date more than once per month and 37.8% kept food as leftovers for more than 5 days.

Impact on food practices

Studies explored both whether a specific source of information had an impact on food choice as well as participant’s perceptions on whether a source would impact their decision making. Ong et al. [59] in their questionnaire study exploring nutritional knowledge, competencies and attitudes found that of their 400 Singaporean participants aged 65 and above, 78.8% said that nutritional values of foods would influence their food choices. Jeruszka-Bielak et al. [55] found that participants who received counselling from a trained dietitian/nutritionist had an improved nutritional knowledge and attitude when compared to the control group in their study. While 71% of participants in Vella et al. [60] said that advice from a healthcare professional would help increase consumption of functional foods. Turner et al. [65] who was looking at online delivery of nutritional information found that if information is individually tailored for example by adults being able to enter their own data and receive feedback, this would be useful and avoid a "one size fits all approach". González-Contreras et al. [53] undertook secondary analysis of the Chilean National Health Survey to determine the association between reading food labels and whether respondents met nutritional guidelines. Although they found that those who read these labels met the nutritional guidelines for fish, dairy, whole grain cereals, pulses fruits, sugared drinks and water this was not the case for the consumption of vegetables and sweetened fruit drinks.

Gender differences

Although Heuberger and Ivanitskaya [54] who undertook a survey with 1100 older adults (65% women) in the USA did not find differences in preferred sources of nutrition information between men and women, a number of other studies did find differences. Oliveira et al. [58] whose participants comprised 54% women and 46% men found that a higher proportion of women preferred to receive information through practical cooking sessions (38.5%) than men (28.6%) (p = 0.044). Ong et al. [59] found that women were more likely to use television, radio and friends as a source of nutrition information, and McKay et al. [57] who undertook their survey in Boston with 176 older adults (50.6% women and 49.4% men) also found that women relied on friends more often than men. However, this was in contrast to Jeruszka-Bielak et al. [55] who found that 39% of men preferred friends and family as sources of nutrition information versus 33% of women. This study also found that more women than men preferred books and magazines (61% vs 49%), while more men preferred internet (43% vs 35%). González-Contreras et al. [53] looked at gender differences in the reading of warning food labels in the Chilean National Health Survey and found although not significant (p = 0.095) that more women than men read food labels. Of the 1510 participants (64.4% women, 35.6% men) 54% read warning food labels. Of the men who took part 32.8% read food labels and of the women who took part 67.1% read the warning food labels.

Education levels and skills

Educational level impacted preferred sources and use of information. Oliveira et al. [58] found that those with a higher educational level preferred leaflets with text and audiovisual materials (p values 0.013, 0.027 respectively). While McKay et al. [57] found that those with more than 4 years of college education (n = 92) were more likely to use newspapers with a higher reading age (the New York Times, Time, Newsweek) and national public radio. However, those with less than 4 years of college education (n = 84) were more likely to use magazines (specifically Good Housekeeping), neighbours and doctors, although the figures were small. Heuberger and Ivanitskaya [54] found that a higher percentage of those with a lower level of education were more likely to refer to a professional source of nutrition information than those with a higher level of education (<12 years 73% of women, 74% of men, versus >16 years 67% of both women and men). González-Contreras et al. [53] found that those with a higher edcation level were more likely to read warnings on food labels and Vella et al. [60] found that those with a higher education level were more likely to be aware of food claims on food labels. Ong et al. [59] found that a higher educational level facilitated being able to seek and critically appraise information and being able to use the internet. Turner et al. [65] also found that skills and competencies impacted preferred sources of nutrition information. They found that there was a need for digital skills in order to be able to access information online. In the participatory study, discussions indicated that while participants were themselves confident with the use of online sources, having the option to print off a hard copy of information may make the source more accessible to those who were not so confident. The hardware used to access the internet was also found to be impacted by skills and competencies. While mobile phones were found to be useful for their ready availability, lack of confidence in their use and the small screen size limited their usefulness for all older adults.

Trust and conflicting messages

Trust in nutrition information and concerns about conflicting messages in sources was identified across eight of the 15 studies. Duerr [61] found that when consulting about nutrition their participants said they would go to the person they respected or who was recognized in their field. This was not necessarily doctors who they felt did not always know very much about nutrition. Jeruska-Bielak et al. [55] found that dietitians held a high level of trust (50%) however, this was alongside books and magazines on health (49%) and doctors (42%). Rueter et al. [64] found that their participants trusted health care professionals (HCPs) in general, and Vella et al. [60] suggest that trust in advice from HCPs impacts food choice (71% said advice on functional foods would help increase consumption). Nationally available nutrition information was found to be a trusted source by Maccharles and Fox [63] and Farrell et al. [51]. Although Farrell et al. [51] found that participants trusted the regulatory framework for nutrition information, they felt that the scientific information could be more clearly linked to the guidance to help with trustworthiness. Turner et al. [65] also found that having access to scientific information backing up the advice as well as ensuring the information was up to date would ensure that a source was trusted.

Lack of trust and a feeling of being deceived was identified when accessing sources of nutrition information. Gustafsson and Sidenvall [62] found that women who said they were influenced by mass media and health authorities felt frustrated by different messages about food and health and did not know whom to believe. Rueter et al. [64] who sought to explore factors that influenced food choice with 35 older adults through semi-structured interviews found that although endorsement of specific foods in mass-media, specifically television and magazines, has the potential to influence food choice, participants experienced contradictory information and a feeling of being deceived by information on food labels.

Strengths and limitations

The research team comprised subject and research experts [JM,AD,EB,TI], and members of the university’s Public Involvement in Research Group with progress monitored by the public advisory group meetings held to support the study. The study involving searches across three databases was strengthened with an update in 2025. The team is confident that a wide range of search terms were incorporated; however, relevant search terms may have been omitted. While the research team acknowledges the relatively low number of included studies related to yield, this potentially indicates the small amount of research undertaken on this topic with free living older adults who do not have diagnosed medical conditions. The level of funding meant that the review process was limited to searching databases holding published research. As searching unpublished sources of studies was not part of the search process, this may have unintentionally excluded relevant research. While two of the databases (CINAHL and Scopus) include grey literature, these only extend to dissertations and conference proceedings. However, while dissertations would have been eligible for inclusion if they met the study design criteria, none were included, and conference proceedings were not eligible for inclusion. While the study is limited in generalizability to the UK and generally with one study involving participants from the UK [55], and just two studies recruited participants nationally [53,55], participants from 13 countries are represented in the current study. Overall, more women than men are represented as participants across the study. This may reflect social norms [86,87] and or be because women may be more interested in food-related issues so are more likely to take part in food related studies and they may have more nutrition knowledge than men and so may feel more confident in taking part in research about this topic [66].

Further research and implications

The scoping review has identified a need for further research in this area, particularly in the UK. Future work could examine the role of, and advice given to older adults, about food and nutrition by health care professionals, as they were often a preferred and trusted source of nutritional information. As a wide range of sources are accessed and used, these are likely to reveal conflicting information and lead to mistrust in the information provided. Research is needed to explore the effectiveness of different sources of nutrition information in changing dietary behaviour. In order to identify the impact of sources on older adults, research should include a greater focus on information received on food choice.

The study findings will be of value particularly to nutrition and dietetic professionals working with older adults. Opportunities to assist in interpreting nutrition information sources such as food labels and exploring views and opinions about nutrition information accessed by older adults should be taken during consultations or nutrition communication events. An increased awareness of the possession of embodied nutrition knowledge, the value placed on practical sources of information, and those from trusted sources should inform nutritional consultations with older adults. When designing nutrition information resources, health care professionals should take the opportunity to make use of the inherent embodied knowledge and skills possessed by older adults in their development. The increased emphasis on communication within healthcare through digital and online formats mean there is a need for more research to co-develop and evaluate online age-friendly nutrition communication tools.