Nutritional support in critical illness

What is nutritional support in critical illness?

When someone is critically ill, their body burns through its energy and protein stores very fast to fight the illness. At the same time, they often cannot eat — because they are sedated, on a breathing machine, or too unwell to swallow safely. Nutritional support is how the team gives the body the energy, protein, fluids, vitamins and minerals it needs during this time.

The usual first choice is feeding through the gut (called enteral nutrition), most often using a soft tube passed through the nose into the stomach. This keeps the gut working and is gentler than feeding into a vein. If the gut cannot be used, nutrition can be given straight into the bloodstream through a drip (called parenteral nutrition).

Nutrition in critical illness is carefully balanced. Too little does not support healing; too much, too soon can cause its own problems. The team usually starts gently and builds up, guided by a dietitian and regular blood tests.

Nutritional support does not stop the body losing some muscle during serious illness — that is part of being critically ill. But it limits the loss, supports the immune system and healing, and helps lay the foundation for recovery and rehabilitation afterwards.

Types, options & approaches

There may be different ways to do this. The right approach depends on the clinical question and your circumstances.

Options at a glance

These are the main approaches described in this guide. The right option depends on the diagnosis, your goals and what your clinician thinks is safe.

Preparing for your treatment

• There is little for a patient to prepare — feeding support is started by the team based on how unwell the person is.
• Tell the team about food allergies, intolerances, diabetes, swallowing problems, or any religious or personal dietary needs.
• Mention any history of an eating disorder, very poor recent intake or alcohol use, as feeding sometimes needs to start more slowly and with extra monitoring.
• Share what the person normally likes to eat and drink, which helps when they start eating again.
• Families can ask how their relative is being fed and whether a dietitian is involved.
• Ask whether and when it will be safe for the person to have sips, ice chips or oral care for comfort.

What happens

If someone cannot eat safely, the team usually starts gut feeding within the first day or two. A soft tube is passed through the nose into the stomach; its position is checked (often with a simple test on the fluid drawn back, and sometimes an X-ray) before feed is given. Liquid feed is then run in slowly through a pump, building up over hours to days towards a target worked out by the dietitian.

The team checks how well the feed is being absorbed, watches blood sugar and salts with regular blood tests, and adjusts the feed. Feeding may be paused around procedures or if the gut is not coping, then restarted.

If the gut cannot be used — for example after some bowel surgery or if the bowel is not working — nutrition can be given into a large vein instead. This needs a dedicated drip line and closer blood monitoring.

As the person recovers and can swallow safely, tube feeding is gradually reduced and normal eating is built back up, often with high-energy supplements and support from a dietitian and, where needed, a speech and language therapist.

Is this treatment right for me?

A good consultation should explore whether it's the right choice for you now — including reasons to wait or consider something else.

Before you decide

Use this as a shared-decision checklist. The aim is not just “can this be done?”, but whether it is right for you, now, with the risks and alternatives clearly understood.

The most important early risk is refeeding syndrome — if someone has eaten very little for days or weeks, feeding too fast can cause dangerous changes in body salts. The team prevents this by starting gently and checking bloods. Ask whether your relative is at risk of this, how feeding is being monitored, and what the plan is for getting back to normal eating.

Published figures to discuss

How well nutrition is tolerated and how quickly someone recovers depends heavily on the underlying illness, the person's age and prior health, and how much they had been eating before. Robust single percentages for complications like refeeding syndrome or aspiration are hard to apply to an individual because they vary widely by situation. We therefore describe these risks in plain words rather than fixed numbers, and your team can explain the specific risks for your relative.

These are literature figures, not a personalised prediction. Your own risks and likely benefits depend on your circumstances, your health, and how your care is carried out and followed up.

What happens afterwards

Nutritional support is part of recovery rather than something to recover from. The aim is to feed the body safely while it is unwell, then move back towards normal eating as the person gets better.

• A poor appetite and feeling full quickly for several weeks
• Food tasting odd, too salty or too sweet while taste buds recover
• A sore mouth or throat after a breathing or feeding tube
• Slow weight and muscle regain even when eating well
• Needing smaller, more frequent meals and snacks at first

Aftercare

• Eat little and often — small meals plus two or three snacks a day are usually easier than large meals.
• Choose nourishing, higher-energy foods and drinks while appetite is poor, as advised by the dietitian.
• Sit upright while eating and for a while afterwards to help digestion and reduce reflux.
• Keep well hydrated unless told otherwise, and look after your mouth (oral thrush is common and treatable).
• Take any prescribed supplements or vitamins as directed.
• If you go home with a feeding tube, follow the training given and keep emergency contact details to hand.
• Tell your GP or dietitian about ongoing weight loss, swallowing problems or persistent poor appetite.

• List of allergies, intolerances and dietary or religious needs given to the team
• Note of usual foods and drinks the person enjoys
• Questions for the dietitian written down
• If tube feeding at home: training completed and supplies arranged
• Contact number for the dietitian or nutrition team
• Plan for help with shopping and cooking after discharge

⚠ Get urgent help if…

• Coughing, choking or sudden breathlessness during or after feeding
• A feeding tube that has clearly moved, come out, or now causes pain
• Vomiting, a swollen painful tummy, or feed not going down
• Signs of a line infection: fever, shivering, or redness around a drip site
• New confusion, weakness or palpitations soon after feeding restarts (possible salt disturbance)
• At home: persistent vomiting, no urine, or being unable to keep fluids down

Who to contact: your clinician, clinic or test provider first (keep their number to hand). For urgent advice when you can't reach them, call NHS 111. In an emergency, call 999.

General guidance — it doesn't replace the specific advice your specialist gives you.

Results & realistic expectations

Good nutritional support means the body is fed safely through the illness, muscle and weight loss are limited as far as possible, and the person is set up to start eating and rebuilding strength as they recover. Progress is gradual and is judged alongside the overall recovery, not by weight alone.

Nutrition cannot stop all the muscle loss of serious illness, and it does not by itself speed up recovery from the underlying problem. What it does is give the body the building blocks to heal and to respond to rehabilitation.

Most people return to normal eating as they recover, though appetite, taste and weight can take weeks or months to fully recover. A small number need tube feeding for longer, or permanently, and are supported with training and a clear plan. Rebuilding muscle and strength after critical illness is a slow process that continues well after leaving hospital.

Related tests, treatments or support

Nutritional support works closely with the rest of critical care — sedation and pain control, physiotherapy and rehabilitation. Good nutrition supports the strength needed for physiotherapy, and a speech and language therapist may assess swallowing before normal eating restarts. A dietitian usually stays involved through recovery.

Follow-up & long-term care

The dietitian and nutrition team review feeding regularly during the stay and plan the return to normal eating. If tube feeding continues at home, a home nutrition team and the GP provide ongoing support. Lasting weight loss, swallowing difficulty or poor appetite after discharge should be reviewed by the GP or dietitian.

• Continue any high-energy diet or supplements advised until weight and strength recover
• Attend dietitian or nutrition team follow-up if arranged
• If feeding at home, keep to the training and cleaning routine and keep supplies stocked
• Build meals back up gradually with snacks and nourishing drinks
• Tell the GP about ongoing weight loss, swallowing problems or low appetite

Repeat, follow-on and what comes next

• Feeding tubes commonly need repositioning or replacing during a stay.
• The feeding method may be switched (for example from gut to vein and back) as the gut recovers.
• Feed targets are adjusted up and down as the person's condition changes.
• Some people need feeding support to continue at home, with training and review.

Ask what happens if the result is unclear or needs repeating, and what is included if further tests or follow-up are needed.

What good aftercare looks like

• A named dietitian involved in planning feeding and the return to normal eating.
• Clear monitoring of blood salts and sugar, especially when feeding starts.
• Swallowing assessed by a speech and language therapist before food is reintroduced where needed.
• Practical advice on eating little and often, with nourishing foods, during recovery.
• Proper training, supplies and a contact number for anyone going home with tube feeding.

What affects the cost

Costs vary a great deal between people and providers, and we don't publish prices. What matters is understanding what drives the cost and making sure your quote is complete. The main things that affect it:

• Whether feeding is through the gut or into a vein (intravenous feeding costs more to provide and monitor)
• How long nutritional support is needed
• Dietitian and speech and language therapy input
• Blood tests and monitoring required
• Special feeds, supplements or equipment
• Any procedure to place a longer-term feeding tube (PEG)
• Home feeding equipment and support if needed after discharge

• Whether nutritional support is included within the critical care daily charge or billed separately
• Whether dietitian input is included
• What monitoring and blood tests are covered
• What happens, and who pays, if intravenous feeding or a feeding-tube procedure is needed
• Whether speech and language assessment of swallowing is included
• Any costs of home feeding equipment and support after discharge

On the NHS? Nutritional support in critical illness is a standard part of NHS critical care, planned and monitored by doctors, nurses and dietitians; it is not usually a separate private choice but part of the overall care.

You're entitled to your total cost in writing — including reports, follow-up and what happens if the result is inconclusive — before you decide.

Consent traps and marketing red flags

These are not small details. They are often where patients lose choice, time to reflect, or realistic expectations.

Choosing a specialist safely

• Check the specialist is on the GMC Specialist Register for this area.
• Make sure they work at a CQC-registered service, and look for membership of the relevant Royal College or professional body.
• You're entitled to time to consider and to have your questions answered before you agree — the specialist who looks after you should explain it, not a salesperson.
• Be wary of pressure: time-limited offers or deposits taken before you've had time to think are red flags, not bargains.
• You're entitled to your total cost in writing — including any follow-up — before you decide.

How Vuemedics verifies every consultant →

Take this to your consultation. A good specialist will welcome every one of these.

• How is my relative being fed, and why has that method been chosen?
• Is a dietitian involved in planning the feeding?
• Is my relative at risk of refeeding problems, and how is that being watched?
• When and how will normal eating and drinking be restarted?
• Will swallowing be checked before food is offered?
• Is there any chance feeding will be needed at home, and what support is there?
• Are you on the GMC Specialist Register for this area, and which Royal College or professional body are you a member of?
• Will you be the specialist who carries out my treatment, and who looks after me afterwards?
• What are the risks for someone like me, and how often do your own patients have a problem or need it repeated or redone?
• What does a realistic result look like — and what can this treatment not achieve?
• What are my options, including waiting, doing nothing for now, or choosing a different approach?
• Can I have written information, results and aftercare instructions in a format I can use, including any accessibility or communication support I need?
• What is the total cost in writing, including any follow-ups, and how much time do I have to decide?

Find a verified specialist for nutritional support in critical illness

Every consultant is GMC-checked and independently reviewed. Search by postcode and distance, or switch to a map. Ordered by rating, relevance and recency — never by who pays.

How we made this page

Medically reviewed by a GMC-registered consultant. Written in plain English, checked against NHS, NICE, GMC and relevant Royal College / specialist-society guidance, and kept under review. No clinic paid to appear on this page, and we publish no pricing. This is general information to help you prepare — it is not a substitute for advice from your own clinician. How we review our guides →

Source hierarchy: UK regulator and NHS/NICE guidance first, then relevant Royal College or specialist-society guidance, then peer-reviewed evidence for procedure-specific figures where available.

Sources & standards: British Dietetic Association — Nutrition in hospital after critical illness ICUsteps — Eating well to get better NICE CG32 — Nutrition support for adults Faculty of Intensive Care Medicine — Guidelines for the Provision of Intensive Care Services (GPICS)

Reviews reflect patients' experience of care, not clinical outcomes. For procedure volumes and outcome data see PHIN.

Last medically reviewed 2026-09-21. Spotted something wrong or out of date? Report an error in this guide.