Synopsis
Identify clinically important undernutrition and unexplained weight loss early, distinguish poor intake from disease and absorption causes, and restore nutrition safely through food, oral, enteral or parenteral support matched to goals and function.
- Screen all hospital inpatients on admission and weekly, and screen community or care-home patients when clinical concern exists, using a validated tool such as MUST.
- NICE defines malnutrition risk through low BMI, significant unintentional weight loss or little or no nutritional intake, interpreted with disease and fluid state.
- First-line assessment measures weight trajectory, BMI, actual intake, swallowing, dentition, gastrointestinal symptoms, function, mood, cognition, medicines and food access.
- Do not attribute weight loss to ageing; investigate cancer, infection, endocrine, organ, gastrointestinal, dental, psychiatric and social causes from the phenotype.
- Food-first care enriches familiar meals, improves meal timing and assistance, treats symptoms and preserves choice; dietitians calculate individual energy and protein needs.
- Use oral nutritional supplements when ordinary and fortified food cannot meet assessed needs, with a defined indication, prescription and response measure.
- Enteral feeding is considered when the gastrointestinal tract works but oral intake is unsafe or inadequate; parenteral support is reserved for an inaccessible or non-functioning tract.
- Before feeding, identify refeeding risk and check phosphate, potassium, magnesium, glucose, renal status and fluid balance.
- For high refeeding risk, NICE advises slow initiation with thiamine and multivitamin support and specialist biochemical and fluid monitoring.
- Review weight, intake, strength, wounds and the underlying cause; nutrition support without functional rehabilitation may not restore independence.
Key red flags
Dysphagia, choking, wet voice, recurrent chest infection or inability to manage saliva requires urgent swallowing and airway assessment.
Unintentional weight loss with mass, bleeding, persistent pain, anaemia, jaundice or change in bowel habit requires expedited cancer investigation.
Confusion, ophthalmoplegia, ataxia or alcohol dependence with poor intake requires immediate parenteral thiamine consideration.
BMI below 16 kg/m², minimal intake for more than ten days or major recent weight loss signals high refeeding risk under NICE criteria.
Severe depression, neglect, food insecurity, controlling care or inability to access meals raises urgent mental-health, safeguarding and social-care needs.
Oedema, dehydration, pressure injury or abrupt functional decline may be a late malnutrition presentation even when body weight appears normal.
Choking, wet voice, fatigue or recurrent chest infection suggests dysphagia and aspiration danger.
Very low BMI, prolonged starvation, substantial recent loss or depleted electrolytes requires a controlled nutrition plan.
Investigation priorities
Identify malnutrition risk and urgency first line.
Management branches
Weight loss, low intake, frailty or acute illness raises malnutrition concern.
- Measure trajectory and MUST, assess actual intake, swallowing, function and immediate refeeding or dehydration danger.
- Investigate disease, medicine, mood, cognition, oral and social causes while setting person-centred nutrition goals.
- Begin food-first or appropriate nutrition support with dietetic oversight and a defined weight, intake and functional review.