Skip to Main Content

Welcome to

Together is a new resource for anyone affected by pediatric cancer - patients and their parents, family members, and friends.

Learn More

Loss of Appetite and Weight Loss

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

Appetite loss during illness is often temporary. However, in some cases, decreased appetite can lead to weight loss, poor nutrition, and other health problems. A dietitian can help you with nutrition strategies. In some cases, health care providers may prescribe medicine to help with appetite. If your child cannot eat enough, nutrition may be given through an IV or feeding tube.

Causes of loss of appetite during treatment

There are many reasons people lose their appetite and have trouble eating during disease treatment. Food may seem less appealing, eating may be more difficult, or they may not feel hungry. Normal eating habits can also be affected 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
  • Stomach and digestive tract disorders
  • Constipation
  • Swelling of the spleen or liver
  • Buildup of fluid in the abdomen
  • Hormone and metabolic changes
  • The disease itself
    • If there is swelling in the abdomen, it may press on organs of the digestive tract and cause fullness
    • If there is swelling 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 is sick, appetite and food concerns can be especially hard. Children may not feel hungry. Even their favorite foods may not interest them. A picky or stubborn eater might become even more so. Medical needs and routine changes can make nutrition challenges worse. This can cause extra stress and worry.

It is important to talk about nutrition and weight concerns with your care team. The care team can make suggestions based on your child’s medical needs and treatment schedule. They can also tell you when more intensive support is needed.

Weight loss during treatment

Loss of appetite and eating less food 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 with certain medications, surgery, or illness. Too much weight loss can be very serious and lead to other health problems.

Your health care team will look at your child’s weight loss based on:

  • Amount of weight loss
  • Rate of weight loss
  • Food and liquid intake
  • Whether there is vomiting or diarrhea
  • Results of laboratory tests and blood tests, called 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. These include fatigue, weakness, and increased risk for falls. Children who lose a lot of weight and have poor nutrition may also be at higher risk for pressure sores. Not having enough essential nutrients can sometimes lead to confusion and changes in mood or behavior. It can also cause problems with heart, kidney, or liver function. Over time, a lack of vitamins and minerals from long-term poor nutrition can put a person at higher risk for complications from treatment.

Ways to prevent weight loss

Good nutrition and getting enough calories are important to encourage normal growth, support daily activities, and prevent medical problems. Depending on your child’s needs, the care team may recommend different strategies. Ways to help prevent weight loss during treatment 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.

Cancer patient eats outdoors.

Find ways to make meals more pleasant - eat with friends and family, choose a new location, or offer choices about when and what to eat.

Tips to manage appetite loss

Good nutrition and healthy eating can be a struggle for families when life is normal. If your child has a serious illness, 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:

Find small ways to encourage healthy habits

  • 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.
  • 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.
  • Use the “feeling better” time between chemotherapy cycles to eat well and boost nutrition.

Plan snacks and meals

  • 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 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.

Stay positive

  • Encourage a positive and healthy relationship with food. Don’t push, threaten, or punish.
  • Find ways to make mealtime more pleasant. Have meals with friends and family, eat outside, try a new location, or use fun plates.
  • Find other ways to help kids enjoy food by including them in recipe finding, meal planning, shopping, cooking, or packing snacks.

Work with your care team to find eating strategies for healthy eating with specific symptoms. These strategies can help with nausea, mouth sores, dry mouth, constipation, or diarrhea.

Find more nutrition tips to help with specific side effects.

Key Points

  • There are many reasons your child’s may lose their appetite during treatment.
  • Work with your care team to make sure your child continues to get some form of nutrition, even when they may not feel hungry.
  • Try simple strategies to encourage healthy habits and good nutrition even during illness.   

Find more information on appetite, weight loss, and healthy eating

Reviewed: September 2022