In the UK, over three million people are malnourished and this can be either undernutrition or overnutrition. It also refers to deficiencies, excesses or imbalances of micronutrients.1

Malnutrition is a major clinical and public health problem in older populations affecting 1.3 million people over the age of 65 years.1,2 Malnourished individuals are also almost four times more likely to be frail3 and half of people who are frail are likely to be malnourished.4

Frailty is used to describe a range of conditions and symptoms such as general debility, sarcopenia (loss of muscle mass and function), weight loss, increased vulnerability and cognitive impairment.5 It can affect all ages and varies in severity.

It is not an inevitable part of ageing, and not all older people will develop frailty, but frail people are at higher risk of adverse outcomes such as falls, delirium, admission to hospital, or the need for long-term care. This is due to a loss of resilience after stresses such as infection, bereavement or changes in environment due to a gradual loss of in-built reserves.6

How to diagnose malnutrition in patients?

A person is classified as malnourished if they meet a set of criteria, which often includes a low body mass index (BMI), significant and unintentional weight loss over a defined period of time and reduced nutritional intake over a defined period of time.

Common signs and symptoms of malnutrition include loss of appetite, weight loss, tiredness, loss of energy, difficulty concentrating, changes in mood such as anxiety and depression, delayed wound healing and a general sense of weakness.7

There are a range of screening tools available including the Malnutrition Universal Screening Tool (MUST), Malnutrition Screening Tool, Nutritional Risk Screening – 2002, Mini Nutritional Assessment, NUTRISCORE (Oncology Patients) and the Short Nutritional Assessment Questionnaire.

As one third of patients over 65 years have malnutrition on admission to hospital,2 NICE recommends that patients are screened on admission or at their first clinic appointment.8 Patients should also be screened during initial registration with a GP surgery, admission to a care home and when there is clinical concern. 

The MUST screening tool is the most frequently used in the UK. It is a five-step tool which is suitable for screening adults across all care settings. It is used to detect those who are malnourished, at risk of malnutrition or obese. The five steps are:

  • Measure height and weight to determine BMI
  • Calculate percentage of unplanned weight loss in the past 3-6 months
  • Establish acute disease effect and score
  • Add scores together to obtain an overall score for risk of malnutrition
  • Use management guidelines and/or local policy to establish a treatment plan.

Diagnosing frailty in patients

Common signs and symptoms of frailty include increased falls, reduced walking speed, weight loss, memory and cognitive impairments, sudden and increased physical disability and delirium.8

There are a range of tests available for diagnosing frailty, although the accuracy of these are uncertain.These include:

  • PRISMA 7 Questionnaire: 7-item questionnaire to identify disability
  • Walking Speed (Gait Speed): gait speed in metres per second over a distance of 4 metres
  • Timed Up and Go Test (TUGT): the time taken to stand from a chair, walk 3 metres, turn and walk back to the chair and sit down
  • Self-Reported Health: asking a patient to rate their health on a scale of 0-10
  • GP Assessment: clinical assessment, including number of medications taken
  • The Groningen Frailty Indicator questionnaire: 15-item frailty questionnaire
  • Electronic Frailty Index: a validated tool commonly used in GP surgeries. It uses existing electronic health record data to identify and severity grade frailty.

The British Geriatrics Society says that individuals should not be labelled as being frail or not frail, but simply that they have frailty and any interaction between an older person and a health or social care professional should include an assessment which helps to identify if the individual has frailty.9

Generally, people with three or more of the above characteristics are considered to have frailty:10

  • Unintentional weight loss
  • Reduced muscle strength and function (sarcopenia)
  • Reduced gait speed
  • Exhaustion
  • Limited mobility and energy expenditure.

If malnutrition and frailty are undetected, this can lead to serious consequences for the patient and the wider healthcare system.

One study found that frailty is associated with increased risk of falls, worsened mobility, disability, hospitalisation and mortality over a 3- or 7-year follow up period.11

Frailty is also an important predictor of mortality and institutionalisation amongst people with mild or severe frailty.12

Women with frailty also have a higher risk of developing activities of daily living (ADL) disability, institutionalisation, and mortality, independent of potentially confounding factors.13 They also had a two-fold increased risk of mortality or two or more falls in the subsequent year compared with women of the same age without frailty.14

Management of frailty and malnutrition

The food first approach is usually the first step in oral nutrition support options, and this could be food fortification, extra snacks, energy-dense meals and snacks, altered meal patterns. Other support measures are oral nutritional supplements, dietary counselling and organisational approaches (i.e. communal dining, protected mealtimes).

What is a food first approach?

Food first is a simple way of providing enhanced nutrition to those who are or at risk of becoming malnourished. It can be useful for patients who still have a good appetite. Strategies include fortifying foods to increase the nutritional density of the diet without increasing the volume of food consumed.

The role of oral nutritional supplements?

According to the ESPEN Guideline on Clinical Nutrition and Hydration in Geriatrics,15 after discharge from the hospital, older persons with malnutrition or at risk of malnutrition should be offered oral nutritional supplements (ONS) in order to improve dietary intake and body weight, and to lower the risk of functional decline.

ONS products typically contain a mix of macronutrients (protein, carbohydrate and fat) and micronutrients (vitamins, minerals and trace elements), and in large enough quantities, some are considered to be nutritionally complete. They are commonly prescribed for hospital or community patients who are struggling to meet their nutritional requirements through an oral diet alone.

They should be given under medical supervision and must be used appropriately. All patients should be screened using a validated malnutrition screening tool such as MUST and be considered at nutritional risk.

Studies have shown that dietary counselling given with or without ONS is effective at increasing nutritional intake and weight.16 Therefore, interventions which combine ONS and a food first approach are commonly used.

Further resources

  • NICE Clinical Guidelines on Nutrition Support for Adults: Oral Nutrition Support, Enteral Tube Feeding and Parenteral Nutrition
  • BAPEN: An Introduction to Malnutrition
  • British Geriatrics Society: Fit for Frailty
  • NHS England Blog: Frailty: What is Means and How to Keep Well Over the Winter Months
  • Royal College of Nurses: Frailty in Older People
  • British Geriatrics Society: Managing Frailty
  • Age UK: Understanding Frailty
  • NICE: Improving Care and Support for People with Frailty
  • AGE UK: Frailty and the NHS Long Term Plan
  • ESPEN Guideline on Clinical Nutrition and Hydration in Geriatrics

Harriet Smith, Registered Dietitian, Aymes International


  1. Gandy, J. Manual of Dietetic Practice, chp. 6.2 Malnutrition (2014).
  2. Malnutrition Task Force. Malnutrition in the UK Factsheet. Available at:
  3. Laur et al (2017) Malnutrition or frailty? Overlap and evidence gaps in the diagnosis and treatment of frailty and malnutrition. Appl. Physiol. Nutr. Metab. 42: 449–458
  4. Bollwein et al. (2013) Nutritional status according to the mini nutritional assessment (MNA) and frailty in community dwelling older persons: a close relationship. J. Nutr. Health Aging, 17(4): 351–356
  5. Lally, Frank, and Peter Crome. 2007. ‘Understanding Frailty’. Postgraduate Medical Journal.
  6. Clegg, A. (2013). ‘Frailty in Elderly People’. In The Lancet.
  7. Gandy, J. Manual of Dietetic Practice, chp. 6.2 Malnutrition (2014).
  8. Turner, Gill, and Andrew Clegg. 2014. ‘Best Practice Guidelines for the Management of Frailty: A British Geriatrics Society, Age UK and Royal College of General Practitioners Report’. Age and Ageing.
  9. Turner, Gill, and Andrew Clegg. 2014. ‘Best Practice Guidelines for the Management of Frailty: A British Geriatrics Society, Age UK and Royal College of General Practitioners Report’. Age and Ageing.
  10. British Geriatrics Society. Introduction to Frailty (2014), Fit for Frailty Part 1. Available at:
  11. Fried, L.P. et al. (2001). ‘Frailty in Older Adults: Evidence for a Phenotype.’ The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences.
  12. Rockwood, K. et al. (2004). ‘Prevalence, Attributes, and Outcomes of Fitness and Frailty in Community-Dwelling Older Adults: Report from the Canadian Study of Health and Aging’. Journals of Gerontology
  13. Bandeen-Roche, K. et al. (2006). ‘Phenotype of Frailty: Characterization in the Women’s Health and Aging Studies’. Journals of Gerontology
  14. Ensrud, K.E. et al. (2008). ‘Comparison of 2 Frailty Indexes for Prediction of Falls, Disability, Fractures, and Death in Older Women’. Archives of Internal Medicine.
  15. Volkert, D. et al. 2018. ESPEN guideline on clinical nutrition and hydration in geriatrics.
  16. Baldwin, C. & Weekes, C. E. (2012) Dietary counselling with or without oral nutritional supplements in the management of malnourished patients: A systematic review and meta-analysis of randomised controlled trials. Journal of Human Nutrition and Dietetics. [Online]