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Loss of Appetite and Weight Loss

Loss of appetite, or not feeling hungry, is a common side effect of cancer and cancer treatments. Appetite loss during cancer is often related to nausea and vomiting due to chemotherapy and other cancer treatments. Certain medicines can change the way food tastes or smells. Decreased appetite may also be due to fatigue, low energy, fever, or just not feeling well.

Appetite loss during cancer is often temporary. However, in some cases, decreased appetite can lead to weight loss, poor nutrition, and other health problems. A dietitian can help families with nutrition strategies. In some cases, doctors may prescribe medicine to help with appetite. If children cannot eat enough, nutrition may be delivered through an IV or feeding tube.

Causes of Loss of Appetite During Cancer

There are many reasons why children lose their appetite and have trouble eating during cancer. Food may seem less appealing, eating may be more difficult, or patients may not feel hungry. Normal eating habits can also be disrupted by schedule changes or being in the hospital. Often, decreased appetite is due to a combination of factors.

There are many reasons why children lose their appetite and have trouble eating during cancer.

There are many reasons why children lose their appetite and have trouble eating during cancer.

Causes of appetite loss during cancer include:

  • Nausea and vomiting
  • Fatigue or low energy
  • Pain
  • Fever and infection
  • Depression, stress, or anxiety
  • Mouth sores or dry mouth
  • Changes in smell or taste
  • Problems swallowing
  • Disorders of the stomach and digestive tract
  • Constipation
  • Swelling of the spleen or liver
  • Buildup of fluid in the abdomen
  • Hormone and metabolic changes
  • The cancer itself
    • If the tumor is in the abdomen, it may press on organs of the digestive tract and cause fullness
    • If the tumor is in the brain, it may affect the nerve signals that control hunger and fullness

Mealtime struggles are common for many families. When a child has cancer, appetite and food concerns can be especially hard. Children may not feel hungry, and even their favorite foods may not be appealing. A picky or stubborn eater might become even more so. Medical needs and routine changes can make nutrition challenges worse, causing extra stress and worry.

It is important for families to talk about nutrition and weight concerns with their care team. The care team can offer suggestions based on the child’s medical needs and treatment schedule and help families know when more intensive support is needed.


Weight Loss During Cancer

Loss of appetite and reduced food intake can cause weight loss. In children, this may be a failure to gain weight during periods of growth. Some weight loss may be normal, especially after chemotherapy, surgery, or illness. Too much weight loss can be very serious and lead to other health problems.

The healthcare team will evaluate a patient’s weight loss based on factors such as:

  • Amount of weight loss
  • Rate of weight loss
  • Food and liquid intake
  • Whether there is vomiting or diarrhea
  • Results of laboratory tests and blood chemistry studies
  • Weakness, loss of strength, or problems doing daily activities
  • Emotional or behavioral factors

Families should be aware of potential problems that may occur with poor nutrition and weight loss including fatigue, weakness, and increased risk for falls. Patients who lose a lot of weight and have poor nutrition may also be at higher risk for pressure sores. Nutrient imbalances can sometimes lead to confusion, changes in mood or behavior, or problems with heart, kidney, or liver function. Over time, a lack of vitamins and minerals from prolonged poor nutrition can put a patient at higher risk for complications from chemotherapy.

Children with cancer are more likely to have low levels of certain vitamins such as vitamin A, vitamin C, vitamin D, and zinc. This may be due to a variety of reasons such as diet, digestive problems, or changes in metabolism due to cancer or cancer treatments. Over time, vitamin deficiencies can cause problems such as slow wound healing, decreased immune function, infection, weak bones, and fatigue. It is important for patients to eat a balanced diet during and after treatment. Getting vitamins and nutrients from foods is preferred when possible. The care team may recommend specific diet changes to increase intake of micronutrients. In some cases, a vitamin or multivitamin supplement may be recommended. Always let your doctor know before starting a new supplement. Some supplements can be harmful or interfere with treatment.

Life-threatening or advanced illness can cause a weight loss syndrome called cachexia. Symptoms include weight loss, loss of appetite, decreased muscle, loss of strength, weakness, and fatigue. Tests may show certain chemical changes in the blood or increases in metabolism. Even with nutrition support, patients with cachexia usually continue to lose weight to some degree. This is often seen in advanced cancer or at the end of life. Management of cachexia requires a multidisciplinary care team to help meet nutrition and medical needs.

Pediatric cancer patients, especially teens and young adults, can develop eating disorders such as anorexia nervosa or bulimia. This is not common. But adolescent patients face developmental and emotional challenges just like other teens, sometimes even more so. Factors such as poor body image, feeling out of control, family stress, anxiety, depression, or previous history of an eating disorder can increase risk. Because loss of appetite, weight loss, and vomiting are common during cancer, an eating disorder might not be suspected. If an eating disorder is suspected, talk with your doctor who may refer you to a specialist.

Ways to Help Prevent Weight Loss

Good nutrition and getting enough calories are important to encourage normal growth, support daily activities, and prevent medical problems. Depending on patient needs, the care team may recommend different strategies. Ways to help prevent weight loss during cancer include:

Each patient is different, and families should discuss options with their doctor and work with their care teams to manage appetite, nutrition, and weight loss.

Decreased appetite and weight loss are common side effects of cancer and cancer treatments. One way to help with appetite loss is to make meal time more pleasant - eat with friends and family, choose a new location, or use fun plates.

Decreased appetite and weight loss are common side effects of cancer and cancer treatments. One way to help with appetite loss is to make meal time more pleasant - eat with friends and family, choose a new location, or use fun plates.

Managing Appetite Loss During Cancer: Tips for Families

Good nutrition and healthy eating can be a struggle for families when life is normal. During cancer, this can be even more challenging. It may take some trial and error to find what works best for each child. Some general tips to help with loss of appetite are:

  • Keep a food journal. Include time of day, emotions, and physical symptoms. This can help you learn about eating habits and makes it easier to talk with your care team.
  • Use the “feeling better” time between chemotherapy cycles to eat well and boost nutrition.
  • Eat small meals and snacks throughout the day. Try for 3 meals and 3 snacks.
  • Keep snack foods on hand so that on-the-go snacking is easier.
  • Choose nutrient and calorie dense foods such as milkshakes, smoothies, thick soups, pasta, and lean proteins.
  • Try commercially available nutrition drinks. A dietitian can recommend the best option.
  • Add calories to foods by using butter, oil, protein powder, powdered milk, cream, or peanut butter.
  • Offer choices of when and what to eat (within reason). Try to balance less healthy choices with healthy options.
  • Get physical activity throughout the day to increase appetite and help digestion.
  • Keep to a regular routine of sleep, activity, meals, and snacks. Use reminders to eat at regular times, even if it is just a few bites.
  • Find ways to make meal time more pleasant. Have meals with friends and family, eat outside, try a new location, or use fun plates.
  • Encourage a positive and healthy relationship with food; don’t push, threaten, or punish.
  • Find other ways to help kids enjoy food by including them in recipe finding, meal planning, shopping, cooking, or packing snacks.

Families can work with the care team to find eating strategies to cope with specific symptoms such as nausea, mouth sores, dry mouth, constipation, or diarrhea. Find more nutrition tips to help with specific side effects.

Find More Information on Appetite, Weight Loss, and Healthy Eating

Reviewed: February 2020