Eating During Radiation Therapy: What to Expect

If you are having radiation therapy, this page walks through how it may change your eating, what helps, and which symptoms need a call.

Radiation is not like chemo. It mainly affects the part of the body it is aimed at. So whether it changes how you eat depends on the area treated. Radiation to the head, neck, chest, belly, or pelvis is the most likely to cause eating problems. The chest counts because the esophagus, or food pipe, runs through it. Radiation elsewhere may not affect eating much at all.

Radiation to the head and neck can cause a sore or dry mouth, taste changes, thick saliva, and trouble swallowing. Radiation to the chest can make swallowing uncomfortable, because the esophagus gets irritated. Radiation to the belly or pelvis can cause nausea, cramping, or diarrhea. All of these can make it hard to eat enough, so nutrition is an important part of care during radiation.

Soft, moist, mild foods are often easier when your mouth or throat is sore. Think smoothies, soups, eggs, yogurt, cooked cereals, and stews. Sauces and gravies help food go down. Nutrition drinks help when solid food is hard. If radiation is aimed at your belly, bland, lower-fiber foods and plenty of fluids may help for a while. Eating small amounts often helps you hold your weight. So does not skipping meals when your appetite dips.

Tell your radiation team about mouth soreness, swallowing trouble, weight loss, nausea, or diarrhea. They can offer treatments, adjust your supportive care, and refer you to a dietitian. If you cannot eat enough, a feeding tube may be an option; your doctor or dietitian will talk with you about it. NCI says healthy cells usually recover within a few months after treatment ends. Take this page as general background. Your radiation team, and an oncology dietitian if you can see one, can fit it to the area you are having treated.

• Call 911 or go to an emergency department if food or drink goes down the wrong way and you cannot stop coughing or cannot breathe, if you are vomiting blood, or if you are too weak, confused, or drowsy to drink. Do not drive yourself.
• Contact your cancer team at once, day or night, if your temperature reaches 100.4°F (38°C) or higher and you are also receiving chemotherapy alongside radiation. CDC says a fever during chemotherapy is a medical emergency, and an infection during chemotherapy can be life-threatening. If you cannot reach them quickly, go to an emergency department and tell staff you are having chemotherapy.
• Call your care team right away if you have a temperature of 100.4°F (38°C) or higher on radiation alone, if your mouth or throat hurts too much to eat, drink, or sleep, if you cannot keep fluids down, or if you have had diarrhea for more than 24 hours. Dehydration can become dangerous.
• Call your care team within a day or two if you are losing weight without trying, if swallowing keeps getting harder, or if nausea or diarrhea is not settling with the advice you have been given.

• National Cancer Institute — Radiation Therapy Side Effects
• National Cancer Institute — Mouth and Throat Problems and Cancer Treatment
• National Cancer Institute — Eating Hints: Before, during, and after Cancer Treatment
• CDC — Fever and Cancer Treatment