Nutrition
Nutrition during medical treatment
Treatment changes appetite, taste, digestion and immunity. Working around the specific symptom in front of you beats general healthy-eating advice every time.
Chemotherapy
Side effects come in cycles. Plan food around the pattern rather than fighting it each time.
What helps
- Eat well in the days you feel best — usually just before the next cycle — and coast through the worst days.
- Take anti-sickness medication before eating, not once nausea has started.
- Cold and room-temperature foods smell less and are better tolerated.
- Keep bland standbys ready: crackers, toast, rice, potatoes, yoghurt.
- Rinse the mouth with salt and bicarbonate water four times daily to reduce ulcers.
- Use plastic cutlery if food tastes metallic; marinate meat or switch to eggs, fish and dairy.
- Sip fluids constantly; dehydration causes more admissions than poor eating does.
Avoid
- Unpasteurised dairy, raw eggs, undercooked meat and unwashed produce when your counts are low
- Grapefruit and unapproved herbal supplements — real interaction risk
- Your favourite meal on treatment day — a nausea association can put you off it for years
- Strong cooking smells; ask someone else to cook, or eat cold food
Contact your care team if
- · Temperature above the threshold you were given, or feeling suddenly unwell
- · Vomiting that stops you keeping fluids down for more than 24 hours
- · Diarrhoea more than four times above your normal
- · Mouth ulcers preventing eating or drinking
- · Weight loss of 5% or more
Dialysis
The renal diet is individual and changes with your bloods. This is guidance, not a substitute for your renal dietitian.
What helps
- Protein needs go up on dialysis — include a protein source at each meal.
- Take phosphate binders with the first mouthful of food.
- Spread your fluid allowance across the day; keep some for the evening.
- Manage thirst with ice chips, frozen grapes, sour sweets, lemon slices and mouth rinses.
- Appetite is often poor on dialysis days — eat well on the days between.
- Boil potatoes and root vegetables and discard the water to lower potassium.
Avoid
- Potassium-based salt substitutes
- Phosphate additives — look for 'phos' in ingredient lists, and cola
- Starfruit, which is toxic in kidney failure
- Herbal supplements without renal team approval
Contact your care team if
- · Potassium or phosphate results outside your target
- · Fluid gains between sessions consistently above your limit
- · Poor appetite for more than a week, or unintentional weight loss
- · Cramping, palpitations or muscle weakness
Surgery and recovery
Healing raises protein and energy needs substantially, often at exactly the time appetite is lowest.
What helps
- Follow any pre-operative carbohydrate loading instructions — they reduce complications.
- Restart eating as early as your surgical team allows; early feeding speeds recovery.
- Aim for protein at every meal and snack while the wound heals.
- Include vitamin C and zinc sources: citrus, peppers, meat, eggs, pulses, seeds.
- Move as soon as you are allowed; muscle rebuilds with protein plus activity, not protein alone.
- Manage constipation from opioid painkillers early — fluids, gentle movement, prescribed laxatives.
Avoid
- Skipping meals because of hospital timetables — ask for snacks between rounds
- Low-fat 'healthy' choices while you are healing
- Alcohol during wound healing
Contact your care team if
- · Wound not healing, or opening
- · Unable to eat or drink for more than 48 hours after discharge
- · Persistent vomiting, or a swollen painful abdomen
- · Continuing weight loss two weeks after surgery
Radiotherapy
Effects depend on the area treated, build up over weeks, and continue for a while after treatment ends.
What helps
- Head and neck: soft moist foods, sauces and gravies, sips with every mouthful.
- Use prescribed mouthwashes and treat dry mouth actively — it affects eating more than pain does.
- Abdomen or pelvis: reduce fibre and fat temporarily if diarrhoea develops, and rehydrate with salt and sugar solutions.
- Eat before treatment appointments if the journey is long.
- Expect fatigue to peak two weeks after treatment finishes — keep easy meals available then.
- Weigh weekly; head and neck radiotherapy causes rapid loss without early intervention.
Avoid
- Acidic, spicy, rough or very hot foods with a sore mouth or throat
- Alcohol and smoking during head and neck treatment
- Applying creams or oils to the treatment area before a session
Contact your care team if
- · Unable to swallow enough to maintain weight
- · Pain not controlled by current medication
- · Diarrhoea with dehydration
- · Weight loss of 5% or more
Long-term medication
Drugs and food interact in both directions. A pharmacist review once a year is worth an hour of anyone's time.
What helps
- Levothyroxine: empty stomach, and four hours away from calcium and iron.
- Warfarin: keep leafy green intake consistent rather than avoiding it.
- Metformin: take with food to reduce gut side effects; ask about B12 monitoring.
- Steroids: take in the morning with food; expect appetite and glucose to rise.
- Proton pump inhibitors long term: ask about B12, magnesium and calcium.
- Diuretics: take early; watch potassium according to the type you are on.
Avoid
- Grapefruit with statins, some calcium channel blockers and several other drugs
- St John's wort with almost anything, especially HIV drugs, antidepressants and chemotherapy
- Starting supplements without checking interactions
- Alcohol with sedatives, opioids and metronidazole
Contact your care team if
- · New gut symptoms after a medication change
- · Unexplained fatigue, which may indicate a drug-induced deficiency
- · Any supplement you want to start while on treatment
Palliative and end-of-life care
The goal shifts from nutrition to comfort and pleasure. Appetite loss late in illness is part of the process, not a failure of care.
What helps
- Offer favourite foods in tiny portions, for pleasure rather than for calories.
- Let them eat what they want, when they want, in any order.
- Mouth care becomes more important than food: moisten, clean, treat thrush, use lip balm.
- Small sips, ice chips and lollies keep the mouth comfortable when drinking is difficult.
- Sit with them at mealtimes even when they eat nothing — the company still matters.
Avoid
- Pressuring, coaxing or negotiating about food — it causes distress on both sides
- Weighing regularly at this stage unless it changes a decision
- Assuming artificial feeding will help; in the last phase it usually adds burden rather than time
Contact your care team if
- · Pain, nausea or a dry sore mouth that is not controlled
- · Distress about not eating — the team can explain what is happening
- · Any question about whether fluids or feeding would help — ask it, it is a fair question
Tube feeding
Feeding through an NG or PEG tube, at home. Routine matters more than anything else here.
What helps
- Sit upright at 30–45 degrees during feeding and for an hour afterwards.
- Flush before and after every feed and medication, with the volume you were taught.
- Give medications separately, flushing between each; never mix them into the feed.
- Keep the stoma site clean and dry, and rotate a PEG tube as instructed.
- Continue mouth care even when nothing is taken orally.
- Keep a spare feeding set and the company's helpline number where you can find them at 2am.
Avoid
- Blended food down a fine-bore tube unless your dietitian has agreed a plan
- Feeding while lying flat
- Crushing modified-release tablets into the tube
Contact your care team if
- · Tube blocked, dislodged or leaking
- · Redness, pain, swelling or discharge at the stoma
- · Vomiting, aspiration or coughing during feeds
- · Diarrhoea or constipation persisting more than two days
Difficulty swallowing (dysphagia)
Unsafe swallowing causes chest infections and is often silent. Follow the speech therapist's texture level precisely.
What helps
- Sit fully upright; stay upright 30 minutes after eating.
- Small spoonfuls; check the mouth is empty before the next.
- No talking while eating; remove distractions and the television.
- Moisten everything — sauces, gravy, custard.
- Fortify, because texture-modified diets are easily under-nutritious.
- Check the cheek for pocketed food afterwards, especially after a stroke.
Avoid
- Mixed textures such as soup with lumps or cereal in milk
- Dry crumbly foods: biscuits, crackers, plain rice, crusty bread
- Straws and cups that force a fast flow, unless advised
- Eating when very tired — fatigue makes swallowing less safe
Contact your care team if
- · Coughing, choking or a wet gurgly voice during or after eating
- · Repeated chest infections
- · Weight loss, or meals taking longer than 45 minutes
- · Any new difficulty swallowing tablets
Loss of appetite
Very common, and rarely just about food. Work backwards from the cause and shrink what is being asked of them.
What helps
- Eat by the clock rather than by hunger — every two to three hours.
- Small plates, small portions, more often.
- Make the largest meal whenever appetite is best, often the morning.
- Fortify: milk powder, cream, cheese, butter, oil, nut butter, honey.
- Nourishing drinks between meals, not with them.
- Gentle movement and fresh air before meals genuinely helps.
- Eat with someone; people eat measurably more in company.
Avoid
- Large plated meals
- Filling up on tea, water or clear soup first
- Pressure, guilt and negotiation at the table
- Low-fat and diet products
Contact your care team if
- · Weight loss of 5% or more over 3–6 months
- · Eating very little for more than five days
- · Pain, nausea, constipation, mouth thrush or low mood — all treatable causes
- · To ask about appetite stimulants or prescribed supplements
Nausea and vomiting
Anti-sickness medication is the main treatment; food changes make it bearable in between.
What helps
- Take anti-emetics regularly as prescribed, before eating — not only when nausea peaks.
- Dry, starchy foods on waking: toast, crackers, plain biscuits.
- Cold or room-temperature foods; hot food smells stronger.
- Small amounts often; an empty stomach worsens nausea.
- Sip fluids slowly and constantly; ginger tea, lemon or peppermint help some people.
- Rest sitting up after eating; lying flat makes reflux and nausea worse.
- Fresh air, and staying out of the kitchen while food is cooked.
Avoid
- Greasy, fried and very sweet foods
- Strong smells and perfumes
- Drinking a lot with meals rather than between them
- Your favourite foods while nauseated — the aversion can last for years
Contact your care team if
- · Vomiting for more than 24 hours, or unable to keep fluids down
- · Signs of dehydration: dark urine, dizziness, confusion
- · Vomiting blood, or material that looks like coffee grounds
- · Nausea not controlled by your current medication — other options exist
Afya Companion offers education and self-help support. It does not diagnose, treat or replace care from your doctor, nurse, psychologist or dietitian. If something in your health changes, speak to your care team.