Overview
Malnutrition describes the adverse effects on body composition, function, or clinical outcome due to a deficiency of nutrients such as energy, protein, vitamins, and minerals. It is both a cause and consequence of ill health.
Risk Factors
- Risk factors in children and infants:
- Young age
- Children with co-existing illnesses
- Neglect
- Poverty
- Risk factors in elderly people:
- Living alone, particularly without care input
- Institutionalisation
- Hospitalisation
- People with mental health problems
- Diseases affecting appetite, eating, swallowing, or gastrointestinal function
Assessment
Overview
People are considered to be malnourished if any of the following apply:
- A BMI of less than 18.5 kg/m2
- Unintentional weight loss >10% in the last 3-6 months
- BMI of less than 20 kg/m2 and unintentional weight loss >5% in the last 3-6 months
People are considered to be at an increased risk of malnutrition if any of the following apply:
- They have eaten little or nothing for >5 days and/or are likely to eat little or nothing for the next 5 days or longer
- Have poor absorptive capacity and/or high nutrient losses and/or increased nutritional needs due to causes such as catabolism
Screening
Screening should assess BMI and the degree and timescale of unintentional weight loss and reduced eating. The Malnutrition Universal Screening Tool (MUST) may be used and categorises patients into low, medium, and high risk.
Management
Multiple nutritional support methods are used, including oral, enteral, and parenteral techniques. Care must be taken to avoid Refeeding syndrome. NICE suggests the following nutrient prescriptions for people who are not severely ill or injured, nor at risk of refeeding syndrome:
- 25-35 kcal/kg/day total energy (including any energy derived from protein)
- This may require adjusting in overweight patients
- 0.5-1.5 g/kg/day protein
- Adequate electrolytes, minerals, micronutrients, and fibre
