How to Manage Cancer-Related Weight Gain

How to Manage Cancer-Related Weight Gain

Reviewed by Jasper Clinical Board

Last updated 5/24/21

Though certain cancer treatments can cause weight loss due to nausea and loss of appetite, many people are surprised to discover that cancer can also lead to weight gain. 
Weight gain is actually a common side effect of many cancer treatments, and there are several reasons a person could gain weight during cancer treatment. The medications you’re taking, the amount of exercise you are getting (or not getting) and changes in metabolism can all play a role, for example.
Certain kinds of chemotherapy or targeted therapies, like those used to treat breast cancer, can cause weight gain, as can some hormone treatments. Though side effects from cancer treatments vary from person to person, you can ask your doctor if weight gain is a common side effect of your treatment; if so, you may discuss healthy prevention and management strategies.
Lymphedema (swelling due to build-up of lymph fluid in the body) can also create swelling and fluid retention, as can certain types of cancer that cause fluid retention in the abdomen (belly). The latter is known as “ascites,” or a buildup of fluid in the space around the organs. It occurs with many kinds of cancer, including colon, ovarian, and pancreatic cancer. When this fluid builds up, it can cause swelling and discomfort.
In addition, some people gain weight because they are not as physically active during treatment, or because eating more helps to settle feelings of nausea. All of these reasons behind weight gain are perfectly normal, and not a sign of a personal failing. Still, it’s important to discuss any weight gain with your doctor, so they can find out what may be causing this change.
A sudden and unexplained weight gain—rapid-onset bloating, clothes or jewelry that are suddenly tight, or a change of five pounds or more in a week or less—may be a sign of a complication with your cancer or treatment, though this isn’t always the case. Because sudden weight gain could signal an emergency, it’s important to contact your cancer care team immediately and heed their advice, whether it’s to fill a prescription, schedule further, testing or head to the emergency room for treatment.
Weight gain that is slow and gradual might be easily addressed with adjustments to your medication or lifestyle. Your cancer care team can identify the causes behind your weight gain and refer you to the resources that will help address your individual needs.
People who experience weight gain during cancer treatment can sometimes feel self-conscious about their changing bodies. However, actively trying to lose weight during cancer treatment is not necessarily a good idea. 
Because your body and immune system are already under incredible stress due to cancer treatment, most oncologists agree that it’s unwise to deprive your body of essential nutrients through dieting. But if weight gain is a concern for you, there are some steps you can take to maintain a healthy weight during your cancer treatment.
Don’t stand for long periods of time. 
Spending long periods of time on your feet can cause fluids to pool in the lower extremities. Instead, try to elevate your feet when you’re not actively moving about.
Learn to manage symptoms of lymphedema. 
Lymphedema is the swelling of a limb or other body tissue that occurs when vessels that form the lymphatic system are blocked, or there is an increase in lymph fluid. Taking steps to reduce swelling, such as wearing compression garments and performing manual lymphatic drainage, can reduce the water retention and discomfort caused by lymphedema. Learn more about managing lymphedema here
Reduce your salt intake
Research shows that people who eat a diet high in salt report more gastrointestinal bloating. The Centers for Disease Control and Prevention recommends limiting the amount of sodium in your diet to less than 2,300 milligrams a day. To achieve this, try to avoid processed foods and instead cook fresh, using onions, garlic, herbs, spices and vinegar to flavor foods instead of using extra salt. If you do choose processed foods, look for those with "low-sodium" or "no salt added" on the labels.
Fill your glass with water instead of high-calorie drinks
Try to avoid juice, soda, sweetened tea or coffee drinks made with sugar and milk, instead opting for water. To jazz it up, try infusing your water with lemon, lime, mint, or cucumber. In addition to reducing your overall calorie intake, water can tamp down bloating by removing waste from the body.
Exercise. Even when you’re tired, something as simple as a walk around the block can help you feel better in mind, body, and spirit. Exercise has many benefits for people going through cancer treatment, including improvements in body composition, overall fitness and metabolic health - all factors that can help with preventing weight gain. 
Know your triggers. When you’re stressed or sad, you likely reach for certain comfort foods, like bread, pasta, or ice cream. Note your patterns—are you eating because you’re truly hungry, or because you’re feeling down? Being mindful of what you’re eating and why you’re eating it can help you reduce how often you engage in emotional eating.
Eat smaller meals throughout the day. If weight gain is a concern for you, look at small changes you can make to your daily habits. Switching from a fixed, three-big-meals schedule to smaller portions throughout the day can help you to avoid hunger peaks, which can lead to overeating and cravings.
Experiment with healthy alternatives. Studies show that people undergoing chemotherapy can experience strong food cravings. Don’t ignore them! Instead, find healthy ways to honor those cravings—opt for whole-grain bread and crackers instead of those made from refined carbohydrates, or satisfy your craving for ice cream with Greek yogurt. In addition to providing more nutrients in fewer calories, these healthy options can help you feel satiated for longer periods of time.
Avoid fad diets. Any diet that touts a specific “miracle food” or advises eliminating one or more food groups (such as meat, fruits, or dairy) may do more harm than good. If you’re looking for dietary advice, ask your cancer care team if a dietitian is available to develop a plan that works with your specific concerns and cravings.
The most important tool for addressing your weight gain is kindness toward yourself. Remember, your body is under tremendous stress during cancer treatment. Your body needs nourishment to stay strong and repair damage from your treatment. Instead of focusing on your weight during treatment, aim for healthy habits like daily exercise, drinking water, and eating a well-balanced diet full of fruits, vegetables, whole grains, and lean proteins.

The content on this website is intended to provide the best possible information for you, but should not be considered—or used as a substitute for—medical advice. If you have questions about your diagnosis or treatment, please contact your health care provider(s). For questions or comments about this content, please email us at