Undernutrition in the Elderly

By James Collier BSc (Hons) - Consultant in Nutrition and Moderator of Dietetics.co.uk

Undernutrition is becoming increasingly prevalent in the ever-growing elderly population. Is poor nutrition just an inevitable consequence of ageing, or are there reasons which health professionals can address to deal with this problem?

The elderly population is growing, and over the next 50 years the number of people over 75 years is likely to double (Thomas 1998). As a population sub-group, older people are the major users of health and Social Services resources, yet are an economically disadvantaged group. Many elderly people lead healthy and independent lives, but the incidence of frailty, disability and illness increases as they get older. Among independent older people 3% of men and 6% of women are underweight, and in nursing and residential care, these figures rise to 16% and 15% respectively (Finch et al 1998).

A national survey of older people in private household (DoH 1992) found the following:

  • Over half reported long standing illness or disability
  • One in five had difficulty seeing, even with glasses
  • One in ten were unable to walk down the road or manage stairs
  • One in five had been seen by a hospital doctor in the preceding three months
  • Half of the women and a quarter of the men aged 85 years and over were not able to cook a main meal alone
  • Only one in ten received 'meals on wheels'

Not only do older people have practical disadvantages but they also have different nutritional requirements to that of the normal adult population, and health professionals working with this client group must be aware of these fundamental needs. With increased age, people become more vulnerable to malnutrition for many reasons including those listed below:

Factors Affecting Malnutrition in the Elderly

  1. Oral
    • swallowing problems from a stroke, Parkinson's disease or other neurological disorder
    • Worsening dentition and periodontal disease, ill fitting dentures
    • Candida
  2. Manual dexterity
    • frail skin on hands
    • peripheral vascular disease
    • osteo- and rheumatoid arthritis
    • loss of use of hands from a stroke, Parkinson's disease or other neurological disorder
  3. Socio-economic
    • Isolation - limited access to shops
    • bereavement
    • poverty
    • institutionalisation
  4. Malabsorption
    • more prone to infection and thus bacterial overgrowth
    • after previous surgery
    • achlorhydria
  5. Diminished sensory ability
    • Taste changes
    • Less smell perception
    • hard of hearing
    • reduced appetite
  6. General Health
    • Drugs and alcohol
    • Chronic disease and disability

All these above risk factors may affect intake, digestion, absorption, utilisation and metabolism of food and nutrients. It becomes increasingly important for improved quality of the diet, as the total amount of food falls with age.

Oral and pharyngeal health
In the Western World dental health is improving in all ages including the elderly who are more likely to retain their teeth. However, tooth decay still often goes unrecognised in some individuals. Also with malnutrition this can lead to a change in mouth shape, so a person with dentures may find they are not fitting properly.

Oral candida is frequently missed on nutritional assessments if the individual does not present with the typical white plaques. Thrush can lead to significant taste changes and reduced enjoyment, therefore, enthusiasm for food.

Many neurological problems may cause dysphagia, the most common being cerebrovascular accident, and if the individual isn't provided with appropriate textures and advice, food intake is likely to be compromised.

Gut function
Changes in the gut microflora can affect digestion and absorption of nutrients. With a reduced immune system there may be bacterial overgrowth in the gut, or conversely, the use of antibiotics may reduce the beneficial gut flora, leading to diarrhoea or constipation. With the ageing process there is also reduced efficiency of motility of gut muscle.

With increasing age there is greater chance of being alone (death of spouse and adult children), and housebound individuals are more vulnerable of nutritional inadequacy. They may depend on 'meals on wheels' and store cupboard foods. It is particularly a problem in the winter months as it is harder to get to shops. Upon retirement there is also a considerably reduced income for the elderly who are forced to shop locally where food items are generally more expensive and there is reduced selection. As more supermarkets are relocating out of towns it makes it harder for the elderly to access them.

Drug use
Drugs can affect the absorption and metabolism of some nutrients. As a population older people use a large percentage of prescribed medication, and many are often using more than one drug, as well as some over-the-counter medicines. Clinical effects of these drugs on an already less efficient metabolism can be loss of appetite and taste changes from chemotherapy and analgesics, or specific nutrient interactions, for example hypokalaemia with loop diuretics and hypocalcaemia from corticosteroids (Thomas 1998).

Incidence and prevalence of undernutrition in the elderly with acute or chronic illness is greater. Nutritional status may be further compromised by other problems in conjunction with the illness, such as trauma, surgery, infection drug therapy which alter nutrient requirements. This makes recovery even more difficult. Merely being in hospital puts patients at increased risk of malnutrition unfortunately (Webb & Coperman 1996, Wood & Creamer 1996). The elderly are particularly prone to fractures of the large bones due to frailty, instability and osteoporosis (Lehmann et al 1991), which puts huge stress on nutritional requirements.

Assessment of Nutritional Inadequacy in the Elderly

There are a number of methods of assessing nutritional status in elderly subjects, a few of which are briefly discussed below. Unfortunately, not always are any of these assessments performed routinely.

Assessment of nutrient intake
Recommendations for intakes for the population are known as Dietary Reference Values (DRVs) (DoH 1991). These are the 'gold standard' of intakes or energy and each nutrient in the UK. If there is concern of inadequacy of an elderly person's diet a State Registered Dietitian will check the composition of an individual's diet by dietary analysis of food diaries against DRVs.

Laboratory Tests
Laboratory Tests are also indicators of inadequacy, which measure the concentration of a particular nutrient or variable affected by a particular nutrient in a tissue. For example serum haemoglobin, albumin, or individual micronutrients can be measured.

This includes weight, height and Body Mass Index (BMI). All are simple and useful measurements for a quick assessment. BMI can be calculated form the following equation:

BMI = weight in kilograms
          height in metres2

There are reference ranges to see if an individual in under- or overweight.

In some cases, skinfold thickness, arm circumference and grip strength measurements may be taken. These generally need an experienced assessor.

Nutritional Screening
It could be argued that all patients admitted to an acute hospital bed should be screened for nutritional status by qualified nursing staff. Nutritional screening tools with emphasis on use for the elderly population have been devised for the assessing nurse to use his/her professional judgement and consider factors like BMI, recent weight loss, skin condition, respiratory function, dementia, nausea, and many more. Furthermore, it is also argued that nutritional screening should be done routinely in nursing homes or even in elderly patients living at home (Holmes 2000). Tools for these situations are available.

The Role of the Health Professional

Using information gained from assessments there should be action plans in place on how to address the nutritional problems. Nutritional support provided will vary between clinical cases, but could include the use of oral nutritional supplements and input from a dietitian.

As can be seen, there is a complex web of factors affecting nutritional status in the elderly involving the ageing process itself, illness, drug treatment and socio-economic factors. Elderly are as risk if they are in an acute hospital, nursing or residential care or in their own homes. It is the health professional's responsibility to highlight nutritional problems and act upon them appropriately.


Department of Health. 1991. Report on Health and Social Subjects 41 - Dietary Reference Values for Food Energy and Nutrients for the United Kingdom. Report of the panel on Dietary Reference Values of the Committee on Medical Aspects of Food Policy. HMSO
Department of Health. 1992. Report on Health and Social Subjects 31 - The Nutrition of Elderly People. Committee on Medical Aspects of Food Policy. HMSO
Finch S; et al. 1998. National Diet and Nutrition Survey: People aged 65 Years and Over: Volume 1: Report of the Diet and Nutrition Survey. London, The Stationary Office
Holmes S. 2000. Nutritional screening and older adults. Nursing Standard 15(2): 42-44
Lehmann AB; et al. 1991. Normal values for weight, skeletal size and body mass indices in 890 men and women aged over 65 years. Clinical Nutrition 70: 18-22
Lennard-Jones JE (ed.). 1992. A Positive Approach to Nutrition as Treatment. London: Kings Fund Centre.
Thomas AJ. 1998. Nutrition and the Elderly. Nursing Times - Nutrition in Practice 10
Webb GP; Coperman J. 1996. The Nutrition of Older Adults. London: Arnold and Age Concern
Wood S; Creamer M. 1996. Malnutrition in hospitals. The Nurses' role in prevention. Nursing Times: 92: 26, 67-68