Description of the condition

The world population is ageing (United Nations 2013). Age is the strongest risk factor for dementia, therefore the number of people living with dementia is increasing (WHO 2012). Today, more than 35 million people live with dementia and the World Health Organization reports that 7.7 million more cases are identified each year (Sosa‐Ortiz 2012; WHO 2012; Prince 2013). It is estimated that this number will nearly double within the next 20 years (ADI 2009), resulting in high costs (USD 604 billion in 2010; ADI 2010), and a considerable burden to individuals and society. Moreover, patients are also now expected to live longer after first being diagnosed with dementia due to improvements in treatment and care (Wimo 2013). Recent research supports these predictions, as well as the increase in prevalence (Prince 2013); however this is mostly due to ageing. Other risk factors for dementia are declining, which could also in turn lead to a decrease in prevalence (Larson 2013).

The term 'dementia' refers to a syndrome occurring in a group of diseases that are typically of a chronic or progressive nature. It involves disturbance of multiple higher cortical functions, such as memory, thinking, orientation, perception and behaviour, and it affects the ability to perform everyday activities. Deterioration in emotional control, social behaviour or motivation often precedes or accompanies cognitive decline. The most common form of dementia is Alzheimer's disease, which is involved in 60% to 70% of cases. Vascular dementia is also very common. Lewy body dementia and frontotemporal dementia are less frequent forms. However, mixed forms are common and subtypes are indistinct (ADI 2009).

In addition to higher age and genetic factors, there are other modifiable risk factors for dementia, which involve vascular disease and its contributing factors (WHO 2012). Diabetes (Lu 2009), midlife hypertension (Qiu 2005), obesity (Beydoun 2008), midlife hypercholesterolaemia (Anstey 2008), smoking (Lee 2013), stroke (Savva 2010) and physical inactivity (Hamer 2009) have been meta‐analytically associated with an increased risk of dementia in general and a higher incidence of Alzheimer's disease.

The effects of malnutrition and the so‐called 'anorexia of aging' have already been recognised as a problem of the elderly in general (Morley 1997; Di Francesco 2007), however these effects become more severe for those living with dementia. Weight loss and malnutrition are a common problem for people with dementia (ADI 2013) and malnutrition presents from the early (Olde Rikkert 2014) to late stages of dementia (Pivi 2012). The onset of Alzheimer's disease is often preceded by several years by weight loss (Barrett‐Connor 1996; Johnson 2006). With the progression of the condition, people with dementia can develop several symptoms that influence food and fluid intake, with several possible mechanisms. While damage to the brain tissue associated with appetite control can cause anorexia (Grundman 1996), other cognitive impairments can lead to forgetting of meals, impair the ability to make food choices or lead to an inability to communicate hunger and ask for food (Gillette‐Guyonnet 2000). Psychologically, behavioural syndromes associated with physiological disturbance, such as apathy and depression, are common and associated with a decreased interest in food, but they can also cause agitation, aggressive behaviour or wandering, which can both have a negative impact on participation in mealtimes and increase energy expenditure. The senses are also affected, i.e. diminishing senses of smell and taste can reduce appetite (ADI 2013). In severe dementia, patients can develop feeding problems and become dependent on feeding assistance. In addition to problems with motor skills, swallowing problems and an inability to use utensils for self feeding, feeding problems can also include the patient refusing to eat, turning their head away while being fed, refusing to open their mouth, spitting out food, leaving the mouth open and allowing food to drop out, or refusing to swallow (Miller 1971; Watson 1993; Pivi 2012). All of these factors contribute to the high risk of people with dementia becoming malnourished, which not only increases rates of complications, hospitalisation, morbidity and mortality, but also decreases their ability to conduct activities of daily life and thus, ultimately, quality of life (Vetta 1999; Rasheed 2013). These problems present regardless of the setting, i.e. community‐dwelling people with dementia as well as those in institutionalised care can suffer from malnutrition (Roque 2013; Tamura 2013).

Description of the intervention

There are numerous interventions available that are designed to modify the mealtime environment of people with dementia, to modify the mealtime behaviour of people with dementia or their caregivers, or to integrate aspects of both with the intention of improving food and fluid intake and, subsequently, nutritional status. Fixed criteria cannot be provided and many interventions are expected to be complex, therefore we will provide the possible components of interventions. We will use the categories described by Abbott 2013 and Whear 2014 for this. This is by no means conclusive and interventions might not be easy to categorise.

• Environmental modifications

  • Change of routine

  • Change of context

  • Change of ambience

  • Others

• Behavioural modifications

  • Education or training of people with dementia

  • Education or training of caregivers

  • Others

Environmental modifications cover all changes to the physical surroundings, social context and timing of meals. Environmental modifications of the routine of mealtimes could either involve changing how the food is served or changing the times at which and for how long meals take place. Modifications to the context of mealtimes are aimed at which persons are present. This includes all persons present during mealtimes, such as other people with dementia, other residents in nursing facilities, family members and formal or informal caregivers. Modifications to the ambience of mealtimes are concerned with properties of the light, sound, smell or temperature of the immediate or possibly intermediate dining environment. Other examples of environmental modifications could include providing a home‐like environment by means of furniture and decoration or having tableware in high‐contrast colours. Another modification could be to provide complementary food items that the patients can resort to if they so desire, either during or in between mealtimes.

Behavioural modifications cover all changes to knowledge, skill, attitude or habits pertaining to the nutrition of either the person with dementia or those in their immediate vicinity during mealtimes. Behavioural modifications to educate and train people with dementia relate to the knowledge people with dementia have about nutrition, their skills in self feeding and their attitude and habits concerning mealtimes. Modifications to educate and train caregivers, on the other hand, are aimed at those providing assistance to people with dementia during mealtimes, but have similar objectives. Modifications that are not directly aimed at nutrition and mealtimes, but instead at, for example, oral hygiene, general motor skills or general knowledge of the condition, would not be included.

Most of these interventions are likely to be modified, depending on the setting. Environmental modifications are especially expected to differ for community care as opposed to institutionalised care. We expect to encounter complex interventions and will provide more information in the 'Characteristics of included studies' table. This will include a description of which materials or procedures were used, who provided them, how these were delivered and the setting, as well as when and how often the interventions were delivered. We will also provide information on comparator interventions if applicable. These descriptions will at least be oriented towards formal measures to describe complex interventions or adopt a suitable instrument, e.g. TIDieR (Hoffmann 2014) or CReDECI (Möhler 2012).

How the intervention might work

Environmental modifications that change the routine, as well as those that change the context, mostly address the important role of the internalised expectations, preferences and habits of the individual when experiencing mealtimes (Sidenvall 1994; Sidenvall 1999; Fjellström 2008; Aselage 2010; Fjellström 2010; Strathmann 2013). Meals are usually highly standardised and process‐oriented, especially in nursing care facilities. One extreme would be reheated food served in trays at set times every day in a large group of other patients. Individual preferences on how and when food is served can rarely be addressed and mealtimes happen in relative anonymity, even though the aspects just described are important considerations for elderly people (Leslie 2011). Interventions that change these processes, for example by employing more family‐style mealtimes, by serving bulk food in a smaller group, are possibly more likely to cater to the habits, eating patterns and actual hunger of these individuals (Barnes 2013). Presented with this form of liberalisation and a more engaging social context, the overall quality of mealtimes for people with dementia might increase and with greater pleasure derived from this event, they are more likely to increase their food intake as they can choose their preferred food, serving size and time spent eating (Lorefalt 2012). Nonetheless, some form of help during mealtimes is often necessary and providing caregivers, or in the case of institutionalised care improving the ratio of people with dementia to nurses, can prove beneficial (Kayser‐Jones 1997; Marshall 2013), and can be considered an environmental modification. Who is present during mealtimes is an important aspect of context, be it other people with dementia, other residents of nursing facilities, family members and formal or informal caregivers. It is, however, a difficult balance to meet the personal preferences of the persons concerned and also the necessities of support. Environmental modifications that change ambience often address the importance of sensory stimuli for the activity levels and mood of the individual. In institutional care, people with dementia often experience insufficient sensory stimulation and might become prone to apathy, depression or generally decreased activity levels, which might negatively affect participation during mealtimes. An increase in lighting, bright colours or stimulating music might therefore increase activity levels (Forbes 2014). Music can either have the effect of raising levels of activity or a soothing effect when people with dementia are agitated (Vink 2003).

Behavioural modifications to educate and train people with dementia are often designed to improve their capabilities in self feeding. With progressive cognitive decline basic motor skills and hand‐eye co‐ordination suffer. By training people in these skills, they might be maintained for a longer period of time through the progression of dementia or formerly lost skills might possibly be regained. Although the degeneration of brain tissue is irreversible, training in specific skills and thus strengthening their neural representation might delay their loss. Higher dependency in activities of daily living is strongly associated with lower quality of life (Beerens 2013), which in turn affects symptoms like agitation or depression. In general, increased activities outside of mealtimes can decrease agitation (Livingston 2014), which in turn can improve mealtime behaviour. Furthermore, training can aim to support patients in their ability to recognise the context of mealtimes and act accordingly (Cleary 2012). While forgetfulness may lead to skipping of meals, impaired decision‐making, slow food choice and reduced intake, training regarding mealtime schedules or a choice of menus can help to preserve healthy mealtime habits. Behavioural modifications to educate or train caregivers of people with dementia could address their feeding skills or their interaction with their charges during mealtimes. Depending on the severity of symptoms and mealtime difficulties, some sort of assistance becomes necessary in any case, so interventions are not a matter of whether or not assistance is provided, but whether these caregivers are in some way trained to cater for people with dementia who have the aforementioned problems (Simmons 2004). This could be as simple as ensuring that the same caregiver is present during all or most mealtimes of a given patient, which accommodates the social factor of mealtimes. In most societies, eating is a social activity and people with dementia are often excluded from this. This is further emphasised when social contacts change during each mealtime, which is often the case in nursing facilities. Individualised feeding assistance can provide a better social experience during mealtimes and thus increase its overall quality, length, enjoyment and also food intake. Other skills consider how touch, guidance and redirection, or simple verbal cues and even simple scripted conversation can result in greater satisfaction, resulting in more time spent on mealtimes and fewer complications (Amella 2004; Woods 2005).

We will briefly refer to the theoretical considerations of the interventions employed in the studies eligible for this review. We will adopt a suitable instrument for describing complex interventions or parts thereof.

Why it is important to do this review

We chose environmental and behavioural nutritional interventions for this review as they are two obvious possibilities for non‐pharmacological intervention available for home care and institutionalised people with dementia. These aspects of care are often difficult or lacking and there is a growing interest in improving the quality of life, activities of daily living, well‐being and health of people with dementia. We believe that it is important to systematically review the evidence on the efficacy of environmental and behavioural interventions that aim to increase the food and fluid intake of people with dementia, because this could not only decrease the risks associated with malnutrition, but also increase overall quality of life. Interventions that modify food items, diets and recipes will be considered in a separate review.

Several reviews have been conducted to investigate the existing literature on different interventions to support nutritional status or intake (Watson 2006; Pivi 2012; Abbott 2013; Liu 2014; Whear 2014). Most of these reviews are quite recent but either have a different methodological approach or a different focus on setting or study participants. This review will apply the strict Cochrane methodology. Even if no substantial differences in findings are found, a Cochrane review will provide informative and regularly updated evidence for health care providers, formal caregivers and informal caregivers on which to base decisions. For those within community care, as well as in institutional settings, who have recognised the need for interventions to decrease the decline or possibly improve the nutritional status of people with dementia, a thorough investigation of the efficacy of the possible interventions is necessary. Based on the findings, they could then opt to employ one or more of the interventions covered. If no evidence for a positive effect can be found, efforts could instead be directed at more promising interventions outside the scope of this review.