It is estimated that around 3 million people in the UK have malnutrition, around 40% of which are over 65 years old. This article will discuss the practical nursing consideration of malnutrition.

Article by Bruno Mafrici

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It is estimated that around 3 million people in the UK have malnutrition, around 40% of which are over 65 years old (British Association for Parenteral and Enteral Nutrition (BAPEN), 2018). Around 40-45% of adults admitted to hospital are at risk of malnutrition (BAPEN, 2022). Malnutrition is both a cause and a consequence of ill health, and can often be a hidden problem. Malnutrition affects health and wellbeing, impairs recovery from illness, increases hospital admission, morbidity, mortality, cost and can lead to long-term health problems (O'Keeffe et al, 2019; Schuetz et al, 2021). Effective nutrition support services are crucial to prevent, identify and treat malnutrition (National Institute for Health and Care Excellence (NICE), 2012).

There are several definitions of malnutrition in the literature. The Malnutrition Task Force (2021) defines malnutrition as a state characterised by low body weight and/or weight loss, which occurs when a person is not eating well

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The cause and consequence of malnutrition are often multifactorial and more complex than simply a reduction of nutritional intake. 

Some causes of malnutrition include:

  • current nutritional status
  • disease (acute or chronic)
  • inflammation
  • metabolic status
  • medical treatments (including drugs)
  • immobility
  • frailty
  • social aspects

Overall, there are three main causes of malnutrition:

  1. Disease related malnutrition, either with or without inflammation (ESPEN, 2018). This form of malnutrition can be caused by a concomitant specific disease (eg liver disease, Crohn’s disease, cancer, kidney disease) and/or associated with a medication or treatment
  2. Malnutrition related to physical factors, such as poor dentition, pain, limited mobility, frailty not necessarily related to a disease
  3. Malnutrition without disease, related to socio-economic factors or hunger

Some factors related to malnutrition are not modifiable, for example:

  • diagnosis of a disease
  • ageing
  • metabolic status
  • inflammation
  • endocrine changes

Sarcopenia is a progressive and generalised skeletal muscle disorder involving the accelerated loss of muscle

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Unintentional weight loss is the most obvious objective sign of malnutrition. Subjective signs of weight loss should not be underestimated, as these enable additional monitoring of nutritional status and as well as the effectiveness of clinical outcomes (Table 2).


Table 2. Examples of signs and symptoms of malnutrition 





Loose clothing

Recent illness

Percentage of weight loss in a given time

Difficult in swallowing and or cooking


Changes in personal circumstances

Loose denture

Reduced appetite


Disease related to malnutrition

Loss of interest in food

Recent hospital stay(s)

From: Malnutrition Task Force (2021)

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Malnutrition screening

The first step to reduce the incidence of malnutrition is screening. Screening for malnutrition is different from the assessment of malnutrition, and requires the use of a validated screening tool. Screening must be a rapid process, easy to perform by any healthcare professional and a specific action must be undertaken for each score obtained. In the UK, the Malnutrition Universal Screening Tool (MUST) is used widely in both the acute hospital as well as in the community settings. MUST focuses on three mainly objective scores (BAPEN, 2011):

BMI score
percentages on unintentional weight loss score
acute disease score

MUST classifies people into three categorise:

  1. low risk of malnutrition (0)
  2. medium risk of malnutrition (1)
  3. high risk of malnutrition (≥2)

A score of 2 or more requires action to treat malnutrition (BAPEN, 2011). Other malnutrition screening tools can also be used, for example, the Nutritional Risk

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Once malnutrition is identified and a detailed nutritional assessment is undertaken, an individualised nutritional care plan should be development and implemented. This should consider all of the potential modifiable factors (Table 1) including changes in nutritional status over time.

In a systematic review and meta-analysis of 27 trials including 6803 patients, Gomes et al (2019) showed that nutritional support provided during hospitalisation was associated with significantly lower rates of mortality and non-elective hospital readmissions, as well as higher energy and protein intake and weight increase. Six of these studies (n=1583) were from the UK.

Treatment of malnutrition is not limited to the provision of additional energy alone. Instead, it should focus in an overall balance between energy, protein, fluid provision as well as micronutrient, vitamins and trace elements, taking into account the route of nutritional support (Figure 1), current medical treatment and clinical problems, physical and psychological components. Dietary advice

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NMC proficiencies

Nursing and Midwifery Council: standards of proficiency for registered nurses

Part 1: Procedures for assessing people’s needs for person-centred care

2.6 accurately measure weight and height, calculate body mass index and recognise healthy ranges and clinically significant low/high readings

Part 2: Procedures for the planning, provision and management of person-centred nursing care

5. Use evidence-based, best practice approaches for meeting needs for care and support with nutrition and hydration, accurately assessing the person’s capacity for independence and self-care and initiating appropriate interventions

5.1 observe, assess and optimise nutrition and hydration status and determine the need for intervention and support

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British Association for Parenteral and Enteral Nutrition (BAPEN). Introduction to malnutrition. 2018. https://www.bapen.org.uk/malnutrition-undernutrition/introduction-to-malnutrition?showall=&start=4 (accessed 6 November 2023) 

British Association for Parenteral and Enteral Nutrition (BAPEN). Malnutrition Universal Screening Tool. 2011. https://www.bapen.org.uk/pdfs/must/must_full.pdf (accessed 6 November 2023)

British Association for Parenteral and Enteral Nutrition (BAPEN). Malnutrition and Nutritional Care Survey in Adults. 2022. https://www.bapen.org.uk/pdfs/reports/mag/national-survey-of-malnutrition-and-nutritional-care-2022.pdf (accessed 30th October 2023)

Cederholm T, Jensen GL, Correia MITD et al. GLIM Core Leadership Committee, GLIM Working Group. GLIM criteria for the diagnosis of malnutrition - A consensus report from the global clinical nutrition community. Clin Nutr. 2019; 38(1):1-9. https://doi.org/10.1016/j.clnu.2018.08.002 

Cruz-Jentoft AJ, Sayer AA. Sarcopenia [published correction appears in Lancet. 2019 Jun 29;393(10191):2590]. Lancet. 2019;393(10191):2636-2646. https://doi.org/10.1016/S0140-6736(19)31138-9 

European Society for Clinical Nutrition and Metabolism (ESPEN). GLIM! Global Consensus for Diagnosing Malnutrition. 2018. https://www.espen.org/component/content/article/263-glim-global-consensus-for-diagnosing-malnutrition (accessed 6 November 2023)

Ferguson M, Capra S, Bauer J, Banks M. Development of a valid and reliable malnutrition screening tool for adult acute hospital patients. Nutrition. 1999;15(6):458-464.

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