Dr Rachel Pryke highlights key factors to consider when assessing malnutrition risk in primary care, and discusses when and how to offer treatment

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Read this article to learn more about:

  • using the Malnutrition universal screening tool to assess risk
  • physical, social, and psychological factors that influence malnutrition risk
  • treatment and management strategies for people with malnutrition and those at high risk.

Key points

GP commissioning messages

Malnourishment is far from a developing-world concept. Estimates suggest that malnutrition affects approximately 1.3 million people aged over 65 years in the UK, the vast majority of whom (about 93%) live in the community.1 Around one-third of patients in UK hospitals are at risk of malnutrition,2 rising to around 50% in patients admitted to hospital from a care home.3

Worldwide, the coexistence of undernutrition (and/or deficiency of one or more vitamins and minerals) alongside overweight and obesity is a growing problem, and it is linked to escalating non-communicable disease rates. In 2014, more than 1.9 billion adults worldwide were overweight, while 462 million were underweight.4

These trends reflect global changing economic growth, urbanisation, and demographics and, in 2016, led the United Nations to declare a Decade of action on nutrition.4,5

This article will focus on assessing and managing caloric undernutrition rather than specific vitamin or mineral deficiency.

Definition and high-risk groups

NICE Clinical Guideline (CG) 32 defines malnutrition as: ‘a state in which a deficiency of nutrients such as energy, protein, vitamins and minerals causes measurable adverse effects on body composition, function, or clinical outcome.’

NICE CG32 recommends that nutritional support should be considered in people who are malnourished, as defined by any of the following:6

  • a body mass index (BMI) of less than 18.5 kg/m2
  • unintentional weight loss greater than 10% within the last 3–6 months
  • a BMI of less than 20 kg/m2 and unintentional weight loss greater than 5% within the last 3–6 months. 

Malnutrition can occur in people with a normal or raised BMI if there has been significant recent weight loss. Weight loss alone does not indicate malnutrition if it has been achieved through a nutritionally complete diet or resulted from changes to energy balance from altering physical activity levels. 

Factors that affect malnutrition risk can be physical, psychological, or social (see Table 1). It is important to be aware that factors may be interlinked and contribute to overall risk. Conditions that increase risk of malnutrition include:7

  • chronic diseases, especially where gut function affects nutrient absorption, and inflammatory conditions or malignancy, where catabolism leads to loss of muscle and fat mass
  • progressive conditions that affect function, for example, dementia, arthritis, Parkinson’s disease, and other neurological conditions
  • acute illness where there is no food intake for over 5 days, such as post-operatively
  • debility, perhaps due to a combination of frailty, immobility, loss of independence, and a decline in mental state.
Table 1: Malnutrition risk factors
Physical factors  Psychological factors  Social factors 
  • Underlying disease 
  • Dental problems 
  • Swallowing difficulties 
  • Vision problems 
  • Drug interactions/ side-effects 
  • Alcohol intake 
  • Drug intake 
  • Mental state 
  • Bereavement 
  • Presence of multimorbidity 
  • Poverty 
  • Being housebound 
  • Functional limitations 
  • Isolation 
  • Inadequate family support 

Social problems including poverty, functional limitations, isolation, inadequate support, or drug or alcohol dependence also increase the risk of malnutrition (see the case study in Box 1). 

Malnutrition risk should be considered in any patient who has several co‑morbidities, any of which may impact on nutritional status and physical function. For example, risk is likely to increase in patients who take over 10 medications. Consider practical issues around dentition, swallowing, visual problems, and changes in domestic circumstances, such as a recently bereaved spouse who lacks confidence in cooking. 

Box 1: Case example

Josie Jones, a 77-year-old woman, lives alone since being widowed a year ago. She first presented to her GP about 6 weeks ago with fatigue, a history of recent falls, and weight loss of 6 kg, which she attributed to losing her appetite. Josie (a non-smoker) had a pale complexion, wore loose-fitting clothes, and had BMI of 19.5 kg/m2. Her records showed that 2 years prior to the appointment, her BMI was 22 kg/m2. Her GP used MUST to assess malnutrition risk—Josie had a score of 2 indicating that she was at high risk of malnutrition. Her GP used PHQ9 to assess depression risk—Josie had a score of 26 suggesting severe depression. Physical examination was otherwise unremarkable.

Suspicious of underlying malignancy, Josie’s GP arranged for routine bloods, a chest X-ray, and a review appointment. Her GP suggested they discuss medication for depression, and gave her local ‘Food boosting’ guidance while awaiting results from the tests.

At the review appointment 3 weeks later, Josie described an upsetting rift with her daughter, who accused Josie of problem drinking. Josie revealed to her GP that perhaps her daughter was right.

Josie’s blood tests showed mildly deranged liver function tests, reduced glomerular filtration rate consistent with dehydration, and low folic acid.


At the review appointment, Josie’s GP arranged an urgent ultrasound scan, prescribed treatment for depression and low folate, and encouraged Josie to bring her daughter with her to her next review. Her GP discussed local support options for problem drinking. Josie agreed she should stop drinking alcohol and to make contact with her daughter again.

On further review, Josie explained the rift with her daughter had resolved, which helped her to reduce her alcohol intake. Her ultrasound scan and chest X-ray were normal, and repeat renal function testing showed resolution of dehydration. Josie’s BMI remained the same but she said her daughter had just purchased some build-up drinks from the chemist for her, and her appetite was improving. Further monitoring of her weight was arranged a month later to coincide with her depression review.


Isolation, depression after bereavement, plus a family rift led to problem drinking, which in turn led to reduced nutrient intake, falls, and eventually dehydration. Addressing her depression and isolation opened the door for Josie to address her alcohol intake, which resolved her dehydration and enabled her to start improving her nutritional status.

Food labelling

When assessing food intake consider the patient’s understanding of health messages. There is an abundance of food labelling messages and advertising approaches targeted towards specific health concerns, for example, lowering cholesterol, or losing weight (e.g. ‘99% fat free’). Full-fat products are commonly perceived as being unhealthy (‘naughty but nice!’) and only a few products are labelled specifically as being suitable for boosting nutrient intake, such as products aimed at building muscle mass.

A product’s health claims may not be of any relevance to someone who is malnourished, but the individual or their family/carer may not have recognised that the person’s nutritional priorities are different. Even where there is awareness of the need to boost intake, over-reliance on sugary confectionery-type foods may boost calories but without providing the required micronutrient or protein balance. Discussing dietary perceptions, issuing written ‘food boosting’ advice, or considering referral to a dietitian may be appropriate in these cases.


Sarcopenia describes loss of skeletal muscle mass linked with loss of function. This is primarily found in the elderly as physical activity levels decline, and is associated with physical disability, poor quality of life, and mortality. Sarcopenic obesity can occur in some cases (particularly in people with rheumatoid arthritis or neurological conditions); this is where there may be a co-existing increase in body fat, which masks the loss in muscle mass and nutritional decline.8 Physical inactivity, as well as reduced nutritional intake, is linked to sarcopenia, as is low grade inflammation and insulin resistance.8 Presence of sarcopenia may be assessed quite simply by considering gait speed, e.g. time taken to answer the door or to walk in from the waiting room, or ability to stand from sitting in a chair.9 Muscle wasting of the extremities may accompany central obesity.8

Hydration and linked concerns

Nutrition and hydration go hand in hand. If a person is struggling to eat, then they may also be at risk of inadequate hydration. Bladder and continence issues may generate more specific hydration concerns if patients are restricting fluids because of immobility or incontinence. Interventions to address hydration and to reduce risk of acute kidney injury should be considered.

Malnutrition as prognostic indicator

In chronic disease, weight loss and changing malnutrition status may indicate disease progression in the underlying condition, for example, development of malignancy in chronic obstructive pulmonary disease (lung cancer)10 or cirrhosis (hepatocellular carcinoma).11 However, weight loss may predate disease progression and malnutrition can also be partly responsible for clinical decline due to a reduction in resilience to infection and respiratory muscle force. Maintaining good nutrition can delay disease progression.12,13


There is no single test that confirms malnutrition and diagnosis is based on holistic clinical assessment. The Malnutrition universal screening tool (MUST) asks three basic questions:14

  • are you skinny anyway? (BMI score)
  • have you lost weight? (weight loss score)
  • have you stopped eating due to illness? (acute disease effect score) 

The MUST score can be used to tailor intervention choices based on malnutrition risk, where 0 is low risk (continue routine clinical care), 1 is medium risk (observe and review risk), and 2 is high risk (treatment advised)—see Figure 1.14

Algorithm showing the five steps of the Malnutrition universal screening tool (MUST)

Algorithm showing the five steps of the Malnutrition universal screening tool (MUST)

Adapted from: Malnutrition Advisory Group. Malnutrition Universal Screening Tool. BAPEN, 2011. Available at: www.bapen.org.uk/pdfs/must/must-full.pdf Reproduced with permission


Social and psychological factors that affect mealtimes, such as isolation, should be addressed wherever possible. Food fortification (sometimes known as ‘food first’) is a first-line choice for the majority of people with malnutrition in the community.15,16 Approaches include:

  • increasing energy density to improve nutritional content without increasing food volume (e.g. add double cream to full-fat milk). This is particularly useful if appetite is poor 
  • texture modification, such as softer choices, fork mashable, or thick pureed foods  
  • ensuring adequate protein and micronutrient intake, without over‑reliance on low‑nutrient sugary foods such as cakes and confectionery
  • addressing potentially conflicting health messages (such as those about low fat foods) that have little relevance to people who are malnourished
  • advising about alternative options such as over-the-counter nutritional supplements
  • reviewing progress—have first-line approaches helped, or might prescribed oral nutritional supplements (ONS) be required?

Prescribing oral nutritional supplements 

For people with chronic diseases, ONS may be indicated where food fortification approaches have been insufficient.6 Oral nutritional supplements have been shown to improve wound healing, reduce length of hospital stay, and reduce hospital readmission rates, as well as improving quality of life and helping to maintain independence.17 Prescribing ONS is particularly relevant for patients likely to require surgery, for example patients with weight loss who are being investigated for an underlying cancer. Long-term prescribing may also be indicated for patients with malnutrition stemming from bowel disorders. 

Ensure that there are clear goals if prescribing ONS and that these goals are reviewed on a regular basis. Consider nutrient requirements specific to the patient, such as a high‑protein, high­‑fibre, or gluten‑free diet. Prescribing ONS for patients with terminal conditions may be appropriate for improving quality of life, but discuss stopping treatment if benefits are no longer perceived. End‑stage cachexia is not reversible by nutritional support.18

Check your local commissioning policy regarding ONS prescribing. Prescribing guidance is available on the Managing adult malnutrition in the community website.19


Malnutrition is a shared risk factor underpinning an array of physical and social problems. Addressing nutritional problems as part of a holistic approach to care can be a cost-effective as well as clinically effective way of helping patients to manage the impact of co-morbidities and to maintain their independence.  

Key points

  • Inquire, investigate, and treat malnutrition
  • Consider social and psychological factors as well as physical reasons why a person may be malnourished
  • Take a structured approach to nutritional status using a validated screening tool such as MUST
  • Challenge assumptions around malnutrition: it is not a normal part of ageing but may be an accepted part of dying
  • Consider sarcopenia, which is loss of muscle mass and strength/function, even where BMI remains in the normal range
  • Assess hydration in addition to malnutrition; if someone is not eating properly they may not be managing other aspects of their health either
  • Issue ‘food first’ advice where appropriate, and arrange a review to ensure it is effective, e.g. to people living in the community who are at low to medium risk of malnutrition, or where a reversible cause of undernutrition can be remedied
  • Follow your local malnutrition pathway with regard to ONS prescribing. Review prescribing goals regularly. Check compliance and consider nutrient requirements, e.g. high-protein, high-fibre, gluten-free diet.

MUST=malnutrition universal screening tool; BMI=body mass index; ONS=oral nutritional supplementation

GP commissioning messages

written by Dr Rachel Pryke

  • Commissioners should:
    • explore how nutrition and hydration care pathways can be integrated across health care, particularly in nursing and care home settings
    • develop service specifications and management structures to promote coordinated, multidisciplinary care in line with NICE CG326,21 and the associated NICE QS2422 
    • view malnutrition and dehydration as a safeguarding issue and incorporate into local improvement plans23
    • review appropriate prescribing of nutritional supplements via medicines optimisation to encourage improvements in clinical outcomes with financial efficiencies.


  1. British Association for Parenteral and Enteral Nutrition. Introduction to malnutrition. www.bapen.org.uk/about-malnutrition/introduction-to-malnutrition (accessed 24 July 2017).
  2. Russell C, Elia M, on behalf of BAPEN and collaborators. Nutrition screening survey in the UK and Republic of Ireland in 2010. BAPEN, 2011. Available at: www.bapen.org.uk/pdfs/nsw/nsw10/nsw10-report.pdf
  3. Russell C, Elia M, on behalf of BAPEN and collaborators. Nutrition screening surveys in hospitals in the UK, 2007–2011. BAPEN, 2014. Available at: www.bapen.org.uk/pdfs/nsw/bapen-nsw-uk.pdf
  4. World Health Organization. Double burden of nutrition. www.who.int/nutrition/double-burden-malnutrition/en/ (accessed 24 July 2017).
  5. World Health Organization. UN decade of action on nutrition 2016–2025. www.who.int/nutrition/events/2016_side-event_43rd_session-CFS_19Oct_Rome/en/ (accessed 24 July 2017).
  6. NICE. Nutrition support for adults: oral nutrition support, enteral tube feeding and parenteral nutrition. NICE Clinical Guideline 32. NICE, 2006, updated August 2017. Available at: www.nice.org.uk/cg32 
  7. Elia M, Russel C, on behalf of BAPEN and collaborators. Combating malnutrition: recommendations for action. BAPEN, 2009. www.bapen.org.uk/pdfs/reports/advisory_group_report.pdf 
  8. Santilli V, Bernetti A, Mangone M, Paoloni M. Clinical definition of sarcopenia. Clin Cases Miner Bone Metab 2014; 11 (3): 177–180.
  9. Rubbieri G, Mossello E, Di Bari M. Techniques for the diagnosis of sarcopenia. Clin Cases Miner Bone Metab 2014; 11 (3): 181–184.
  10. Mitra M, Ghosh S, Saha K et al. A study of correlation between body mass index and GOLD staging of chronic obstructive pulmonary disease patients. J Assoc Chest Physicians 2013; 1 (2): 58–61.
  11. Teiusanu A, Andrei M, Arbanas T et al. Nutritional status in cirrhotic patients. Maedica (Buchar) 2012; 7 (4): 284–289. 
  12. Banner J, Bowden M, Cotton J et al.Managing malnutrition in COPD. 2016. www.malnutritionpathway.co.uk/files/uploads/Managing_Malnutrition_in_COPD.pdf
  13. Vestbo J, Prescott E, Almdal T et al. Body mass, fat-free body mass, and prognosis in patients with chronic obstructive pulmonary disease from a random population sample: findings from the Copenhagen City Heart Study. Am J Respir Crit Care Med 2006; 173 (1): 79-83.
  14. Malnutrition Advisory Group. Malnutrition Universal Screening Tool. BAPEN, 2011. Available at: www.bapen.org.uk/pdfs/must/must-full.pdf 
  15. Brotherton A, Simmonds N, Stroud M on behalf of the BAPEN Quality Group. Malnutrition matters—meeting quality standards in nutritional care. BAPEN, 2010. Available at: www.bapen.org.uk/pdfs/toolkit-for-commissioners.pdf 
  16. Patients Association. Malnutrition in the community and hospital setting. Patients Association, 2011. Available at: patients-association.org.uk/wp-content/uploads/2014/07/Malnutrition-in-the-community-and-hospital-setting.pdf 
  17. National Collaborating Centre for Acute Care. Nutrition support for adults: oral nutrition support, enteral tube feeding and parenteral nutrition—methods, evidence, and guidance. NCCAC; London, 2006. Available at: www.nice.org.uk/guidance/cg32/evidence
  18. Santarpia L, Contaldo F, Pasanisi F. Nutritional screening and early treatment of malnutrition in cancer patients. J Cachexia Sarcopenia Muscle 2011; 2: 27–35. 
  19. Brotherton A, Holdoway Anne, Mason P et al. Managing adult malnutrition in the community. Available at: malnutritionpathway.co.uk/downloads/Managing_Malnutrition.pdf
  20. NHS England. Guidance—commissioning excellent nutrition and hydration 2015–2018. NHS England, 2015. Available at: www.england.nhs.uk/wp-content/uploads/2015/10/nut-hyd-guid.pdf 
  21. NICE. Nutrition support in adults: oral nutrition support, enteral tube feeding and parenteral nutrition—costing report. NICE Clinical Guideline 32 implementation tools. NICE, 2006. Available at: www.nice.org.uk/guidance/cg32/resources/costing-report-pdf-194884669
  22. NICE. Nutrition support in adults. NICE Quality Standard 24. NICE, 2012. Available at: www.nice.org.uk/qs24
  23. Social Care Institute for Excellence (SCIE). Commissioning care homes: common safeguarding challenges—poor nutritional care. SCIE Guide 46. SCIE, 2012. www.scie.org.uk/publications/guides/guide46/commonissues/poornutritionalcare.asp (accessed 25 July 2017) G