Health A to Z
Malnutrition is a serious condition that occurs when a person’s diet doesn't contain the right amount of nutrients.
It means "poor nutrition" and can refer to:
This topic focuses on undernutrition. Read about obesity for more about the problems associated with overnutrition.
This page covers:
Common signs of malnutrition include:
Read more about the symptoms of malnutrition.
See your GP if:
If you're concerned about a friend or another family member, try to encourage them to see their GP.
Your GP can check if you're at risk of malnutrition by measuring your weight and height, asking about any medical problems you have, and asking about recent changes in your weight or appetite.
If they think you could be malnourished, they may refer you to a healthcare professional such as a dietitian to discuss treatment.
Malnutrition is a common problem, affecting millions of people in the UK.
Anyone can be affected, but it's more common in:
Elderly people are particularly at risk, and weight loss is not an inevitable result of old age.
Read more about the causes of malnutrition.
Treatment depends on the person’s general health and how severely malnourished they are.
The first dietary advice is usually:
Some people also need support to help with underlying issues such as limited mobility – for example, care at home or occupational therapy. If a child is malnourished, their family may need advice and support to address the underlying reasons why this may have happened..
If these initial dietary changes aren't enough, a doctor, nurse or dietitian may also suggest taking extra nutrients in the form of nutritional drinks or supplements.
If the person has difficulty eating that can't be managed by making changes such as eating soft or liquid food, other treatments may be recommended, such as:
Read more about how malnutrition is treated.
The best way to prevent malnutrition is to eat a healthy, balanced diet.
You need to eat a variety of foods from the main food groups, including:
See the Eatwell Guide for more information about the types of food that should make up your diet and the proportions you should eat them in.
Speak to your GP or specialist if you have a health problem that means you're at an increased risk of malnutrition. You may have more complex dietary needs or may need to take supplements.
The main symptom of malnutrition (undernutrition) is unintended weight loss, although this isn't always obvious.
Most people who are malnourished will lose weight, but it is possible to be a healthy weight or even overweight and still be malnourished.
Someone could be malnourished if:
See your GP if you've unintentionally lost a lot of weight over the last few months.
If you notice a friend or family member has lost lots of weight, talk to them about your concerns and encourage them to get help.
Other signs of malnutrition include:
See your GP if you have these symptoms. If you notice these problems in someone else, try to encourage them to get help.
Symptoms of malnutrition in a child can include:
Contact your GP if you're concerned about your child's health or development at any point.
Malnutrition (undernutrition) is caused by a lack of nutrients in your diet, either due to a poor diet or problems absorbing nutrients from food.
Certain things can increase a person's risk of becoming malnourished.
Some conditions that can lead to malnutrition include:
You can also become malnourished if your body needs an increased amount of energy – for example, if it's healing after surgery or a serious injury such as a burn, or if you have involuntary movements such as a tremor.
Some types of medication may increase your risk of developing malnutrition.
Some medicines have unpleasant side effects – such as loss of appetite, diarrhoea or nausea – that could mean you eat less or don't absorb as many nutrients from your food.
The following factors can also contribute to malnutrition:
In the UK, malnutrition in children is commonly caused by long-term health conditions that:
Some children may become malnourished because of an eating disorder or a behavioural or psychological condition that means they avoid or refuse food.
Malnutrition as a result of a poor diet is rare in the UK, but may occur if a child is neglected, living in poverty or being abused. Call the NSPCC helpline on 0808 800 5000 if you're concerned about a child.
Treatment for malnutrition (undernutrition) depends on the underlying cause and how malnourished the person is.
They may be given advice to follow at home, or they may be supported at home by a dietitian or other qualified healthcare professional. In severe cases, treatment in hospital may be needed.
A dietitian will advise about dietary changes that can help.
They may create a tailored diet plan that ensures the person gets enough nutrients.
They may also suggest:
If these measures aren’t enough, taking extra nutrients in the form of supplements may be advised. These should only be taken on the advice of a healthcare professional
For more information and advice, see:
For people who are unable to eat enough to meet their body's needs – for example because they have swallowing problems – an alternative way of getting nutrients may be needed.
This can include:
These treatments are usually first started in hospital, but they can be continued at home if the person is well enough.
Read about how swallowing problems are treated for more information about these feeding methods.
Some people who are malnourished also need extra care to help them cope with underlying issues such as limited mobility.
This may include:
Read more about care and support for feeding and nutrition problems.
Malnutrition in children is often caused by long-term health conditions, for which hospital treatment is often needed. But this isn't the case for all children with malnutrition.
Treatment may involve:
Severely malnourished children need to be fed and rehydrated with great care so can't be given a normal diet straight away. They will usually need special care in hospital.
Once they're well enough, they can gradually return to a normal diet and continue this at home.
It's important that treatment is monitored regularly to make sure it's working. Regular weight and height measurements will be taken, with referral to specialist services if there's no improvement.