Appetite Loss

Approved by the Cancer.Net Editorial Board, 04/2020

Appetite loss or poor appetite are common side effects from cancer and its treatment. This means that you may eat less than usual, not feel hungry at all, or feel full after eating only a small amount.

Ongoing appetite loss may lead to serious complications. These include weight loss, not getting the nutrients that the body needs, and fatigue and weakness from muscle loss, which is called cachexia (see below). These issues can slow recovery and lead to breaks in treatment.

It is important to talk with your health care team if you lose your appetite. They can help find the cause and make sure you are getting the nutrition you need.

Causes of appetite loss

Many different things can cause appetite loss in a person with cancer:

  • Changes in metabolism, which is the body’s process of breaking down food and turning it into energy. Such changes can happen with advanced cancer.

  • Cancer inside the abdomen, which may cause irritation or swelling.

  • An enlarged spleen or liver, which pushes on the stomach and creates a feeling of fullness.

  • Ascites, which is a buildup of protein-filled fluid in the abdomen that may create a feeling of fullness.

  • Medications, including chemotherapy, immunotherapy, and other drugs.

  • Radiation therapy or surgery to any part of the gastrointestinal organs, such as the stomach or intestines.

Other side effects of cancer treatment can also cause appetite loss:

  • Nausea and vomiting

  • Pain

  • Mouth sores and mouth pain

  • Infections in the mouth

  • Dry mouth

  • Difficulty swallowing

  • Difficulty chewing

  • Changes in taste and smell

  • Constipation or diarrhea

  • Pain

  • Fatigue

  • Depression

  • Stress or anxiety

Managing appetite loss

Relieving side effects is an important part of cancer care and treatmentThis is called palliative care, or supportive care. Talk with your health care team about any symptoms you experience and any change in symptoms. Many studies show that starting palliative care early improves outcomes.

If possible, the first step in treating appetite loss is to address the cause. Therefore, your cancer treatment is a key part of improving your loss of appetite. Treatment for conditions such as nausea, pain, mouth sores, dry mouth, pain, or depression may help improve appetite.

Consider the following tips for getting proper nutrition when your appetite is low:

  • Eat 5 to 6 small meals a day, and snack whenever you are hungry.

  • Do not limit how much you eat.

  • Determine which times of day you are hungry and eat at those times.

  • Eat nutritious snacks that are high in calories and protein. This includes dried fruits, nuts and nut butters, yogurt, cheeses, eggs, milkshakes, ice cream, cereal, pudding, and protein bars or granola bars.

  • Carry a snack bag with you and keep your favorite foods on hand for snacking.

  • Increase the calories and protein in foods by adding sauces, gravy, butter, cheese, sour cream, half and half, whipped cream, and nuts or nut butters.

  • Drink fluids between meals, rather than with meals, which may make you feel full too quickly. If you can, drink fluids with additional calories, such as sports drinks with electrolytes.

  • Choose nutritious or filling drinks, such as milk or nutritional milkshakes or smoothies.

  • Ask family members or friends to get groceries and prepare food for you when you are too tired to shop or cook. Also consider buying precooked meals.

  • Try to eat in pleasant surroundings and with family or friends.

  • Try placing food on smaller plates rather than larger plates.

  • If the smell or taste of food makes you nauseous, eat food that is cold or at room temperature. This will decrease its odor and reduce its taste.

  • If you are having trouble tasting food, try adding spices and condiments to make the foods more appealing.

  • If you have changes in taste, such as a metallic taste in your mouth, try sucking on hard candy such as mints or lemon drops before eating a meal.

  • Ask your health care team about ways to relieve gastrointestinal symptoms, such as nausea, vomiting, and constipation. Also tell your doctor if you are having any difficulty managing pain.

  • Try light exercise, such as a 20-minute walk, about an hour before meals. This may help stimulate your appetite. Consult your health care team before starting an exercise program. Exercise also helps maintain muscle mass.

Meet with a registered dietitian for advice on meal planning and symptom management. A dietitian can also decide whether you might benefit from nutritional supplements or digestive enzymes. Ask your health care team if there is a dietitian available at your treatment center.

Your doctor may treat appetite loss and associated weight loss with certain medications, including:

  • Megestrol acetate (Ovaban, Pallace) or medroxyprogesterone (Amen, Depo-Provera, Provera). These are forms of the progesterone hormone that can improve appetite and weight gain but may be associated with a higher risk of blood clots.

  • Steroid medications. These can increase appetite, improve a person's sense of well-being, and help with nausea, weakness, or pain. However, steroids should be used for short periods of time because long-term use is associated with many unwanted side effects.

  • Metoclopramide (Reglan). This helps improve nausea, helps move food out of the stomach, and can prevent feeling full before eating enough food.

  • Dronabinol (Marinol). This is a cannabinoid (called THC) made in the laboratory, which may stimulate appetite. However, it is also associated with higher risk of confusion and should be avoided in adults over the age of 65 or those who are frail.

Sometimes, a feeding tube is placed temporarily through the nose into the stomach. A more permanent tube can also be placed directly into the stomach (called a gastrostomy tube or G-tube) from the abdominal wall if necessary. Many times, however, this approach is not recommended. ASCO guidelines note that this approach is not recommended in most patients with weight loss related to advanced cancer. 

If you are experiencing appetite loss, be sure to let your health care know. They can provide advice as to what is recommended in this situation.

Cancer cachexia (updated 08/2023)

Cachexia, which is also called wasting, occurs when people with advanced cancer experience a complete loss of appetite that leads to both weight loss and muscle loss. Up to 80% of people with advanced cancer have cachexia.

For treating appetite loss in people with cachexia, ASCO suggests that it may be helpful for patients and their caregivers talk with a registered dietitian. A registered dietitian provides a nutritional assessment and counseling about eating and feeding. This includes education about which high-protein, high-calorie, nutrient-rich foods to give a person with cachexia when they can eat. A registered dietitian can also offer advice on safe, practical feeding.

One medication that may be offered to help improve appetite loss and weight loss in people with cachexia is olanzapine (Zyprexa) when given at a low dose once a day. Olanzapine is a drug often used to treat certain mood and mental health conditions. However, research has shown that olanzapine can be helpful in treating nausea and vomiting during cancer and its treatment and can also help improve appetite in people with cancer. If a person with cachexia is unable to receive olanzapine, their doctor may offer them a short-term course of a progesterone hormone or steroid instead (see above). Patients should ask their health care team about the risks and benefits of these medications, including the risk of blood clots related to progesterone hormone use. 

ASCO does not recommend that most people who have cachexia be fed through an IV or feeding tube, as people with cachexia are more likely to experience complications from these treatments and these approaches have not been shown to improve the quality or length of life.

Listen to a Cancer.Net Podcast on cancer cachexia to learn more. This information is based on ASCO recommendations for Management of Cancer Cachexia; please note that this link takes you to another ASCO website.

Tips for caring for a loved one with cancer cachexia

Watching your loved one lose their appetite and weight can cause anxiety and stress. As a caregiver, one of your roles is to make sure that your loved one eats. However, cachexia causes many symptoms in people with cancer that make eating and drinking very difficult. That often makes food a source of increased tension between patients and their caregivers. Here are some tips to consider:

  • Recognize that loss of appetite may be out of your loved one’s control. “Trying harder” to eat does not always work.

  • “Pushing food” on your loved one can make the issue worse, not better. Avoid making food a battle.

  • Recognize that your loved one may ask for food, but by the time you prepare it, they may not want it anymore. This is incredibly frustrating, but very common.

  • You are not a failure as a caregiver if your loved one does not want to eat. This is out of your control.

  • Be creative. Find ways to show you care outside of food, including giving your loved one a massage, holding hands, reading, or playing games.

  • Preparing and eating food is often a major focus of social gatherings. Find ways to support your loved one during social gatherings that do not involve eating food.

  • Make sure you are getting help with caregiving duties and taking time to take care of yourself.

  • Connect with other caregivers to find support and develop creative strategies that may best suit your loved one.

Related Resources

Nutrition Recommendations During and After Treatment

Smart Grocery Shopping for a Healthier You

7 Steps to Meal Planning Mastery

ASCO answers; Appetite LossDownload ASCO's free Appetite Loss fact sheet. This 1-page printable PDF gives an introduction to appetite loss, includes possible causes, treatment options, words to know, and questions to ask the health care team. Order printed copies of this fact sheet from the ASCO Store.