When Eating Enough Is Hard: What to Ask

"I can't eat" is not one problem. It is at least a dozen problems that all look identical from the outside, and each one has a different fix. The most useful thing you can do before an appointment is work out which of them is yours.

Someone who feels full after four mouthfuls needs a different answer from someone whose mouth is too sore to chew, and both need something different from someone whose swallowing has narrowed. Bring the mechanism, not just the complaint.

Try to place exactly where eating breaks down.

• Before food. No hunger at all, or food repels you on sight or smell.
• In the mouth. Pain, sores, dryness, thick saliva, a taste that ruins everything, jaw that will not open wide.
• Swallowing. Food sticks, or swallowing hurts, or you cough after drinking.
• Early on. You feel full within a few bites. This is called early satiety.
• After. Nausea, reflux, bloating, cramps, or diarrhea that makes you dread the next meal.
• Around it all. Fatigue that makes cooking impossible, pain, low mood, or a treatment schedule that eats the day.

That last group matters more than people expect. NCI lists anxiety, pain, depression and fatigue among the causes of appetite loss, alongside the physical side effects.

NCI groups the nutrition side effects by treatment type, and the lists differ in useful ways.

Chemotherapy: appetite loss, nausea and vomiting, constipation, diarrhea, dry mouth, mouth and throat sores, taste changes, trouble swallowing, early satiety.

Radiation therapy: appetite loss, nausea and vomiting, dry mouth, sore mouth and gums, taste changes, trouble swallowing, pain on swallowing, being unable to open the mouth fully, bowel blockage, an inflamed colon, and radiation enteritis, which is irritation of the small bowel from radiation.

Surgery: appetite loss, trouble chewing, trouble swallowing, early satiety.

Immunotherapy: fever, nausea and vomiting, diarrhea, fatigue.

Targeted therapy: constipation, diarrhea, nausea and vomiting, abdominal pain, taste changes, dry or sore mouth.

Stem cell transplant: mouth and throat sores, diarrhea.

Naming yours out loud changes the conversation. "I have radiation enteritis" gets a different response from "food isn't going down."

There are validated tools for this, and you are allowed to request one. The NCI professional summary names the Malnutrition Screening Tool, the Malnutrition Universal Screening Tool, the Patient-Generated Subjective Global Assessment, the Malnutrition Screening Tool for Cancer Patients, and NUTRISCORE.

Two of these have been validated for both hospital and outpatient oncology use: the Malnutrition Screening Tool, often shortened to MST, and the Patient-Generated Subjective Global Assessment, or PG-SGA. The PG-SGA is longer and partly filled in by you.

A formal screen does something an informal question does not. It produces a score that goes in the record, and a score is what triggers a dietitian referral.

Some weight loss during cancer is not about intake at all.

Cachexia is defined in the NCI professional summary as an ongoing loss of skeletal muscle mass that cannot be fully reversed by conventional nutrition support, and that leads to progressive loss of function. The summary describes three stages: precachexia, cachexia, and refractory cachexia, the last usually seen in advanced disease.

This is worth understanding because it changes what success looks like. If cachexia is driving the loss, eating more will not simply reverse it. Nobody has failed. The goal shifts toward keeping strength and comfort rather than hitting a weight number.

NCI is explicit that nutrition goals are individual. For someone at a healthy weight during treatment, the aim is often to preserve lean body mass. For someone with acute malnutrition, it is supporting organ function. Ask which of these is your goal, because the answer decides everything else.

• Your weight now, and your weight before diagnosis. Dates for both.
• What you actually ate and drank in the last 24 hours. Write it down as it happens, not from memory.
• The exact point where eating fails, from the list above.
• Every medicine and supplement, including anti-nausea pills and painkillers.
• Your treatment name and where you are in the cycle.

There are two ways to feed someone who cannot eat enough by mouth, and NCI describes both.

Enteral nutrition uses the gut. Liquid feed goes through a tube: a nasogastric tube through the nose, a gastrostomy tube into the stomach, or a jejunostomy tube into the small bowel. Parenteral nutrition bypasses the gut entirely and goes into a vein through a central or peripheral catheter.

NCI's guidance for transplant patients states the general principle plainly: if the gastrointestinal tract works, enteral nutrition is recommended. Using the gut keeps it working and carries fewer risks than feeding into a vein.

Raising this early is not giving up. For some head and neck radiation plans, a feeding tube is placed before treatment starts precisely because it protects the treatment schedule.

• Call 911 or go to an emergency department if you choke on food or drink and cannot clear it, or a swallow is followed by struggling for breath.
• Call your treatment team straight away, whatever the hour, if the thermometer reaches 100.4°F (38°C) or higher while you are on cancer treatment. CDC treats a fever during chemotherapy as a medical emergency, since infection can take hold quickly when counts are low. No quick answer from them? Go to an emergency department and tell staff you are having chemotherapy.
• Call your care team the same day if a whole day passes without fluids staying down, or eight hours pass with no urine, or standing up makes the room swim.
• Call your care team within a day or two if five pounds have gone in a week, or mouth pain has stopped you drinking properly, or food and liquid keep catching in the throat and drinks set off a cough.

• Which side effect is the main reason I am not eating, and is it treatable?
• Can I have a formal malnutrition screen and a dietitian referral?
• Is my weight loss from low intake, or is this cachexia?
• Is my nausea, pain or low mood being treated hard enough?
• Are there medicines that could improve my appetite, and what are the trade-offs?
• At what point would you consider tube feeding, and would you do it sooner rather than later?

See Eating When You Have No Appetite, Eating When You Have Nausea, Getting Enough Protein During Cancer Treatment, and Nutrition Questions Before Cancer Treatment Starts.

• https://www.cancer.gov/about-cancer/treatment/side-effects/nutrition
• https://www.cancer.gov/about-cancer/treatment/side-effects/appetite-loss
• https://www.cancer.gov/about-cancer/treatment/side-effects/appetite-loss/nutrition-pdq
• https://www.cancer.gov/about-cancer/treatment/side-effects/appetite-loss/nutrition-hp-pdq
• https://www.cancer.gov/about-cancer/treatment/side-effects/infection
• https://www.cdc.gov/cancer-preventing-infections/patients/fever.html
• https://www.cancer.gov/publications/patient-education/eatinghints.pdf