8 Tips for Managing Weight during and after Cancer Treatment

Photo of an array of high-protein foods, including meat, cheese, milk, and nuts.

Cancer patients should eat a variety of foods and especially make sure they get enough protein, which is found in foods such as meat and seafood.

Just after a cancer diagnosis, perhaps the last thing on your mind is how treatment might affect how or what you eat. But cancer itself — along with side effects from treatments such as chemotherapy, radiation, and surgery — can significantly impact your appetite, eating habits, activity levels, and weight.

Most cancer patients lose weight during treatment, though certain therapies — particularly those for hormone-driven malignancies such as breast and prostate cancers — can trigger weight gain. Getting back to a “normal” diet after treatment is completed poses its own challenges. Since significant weight loss or gain can affect your prognosis (chance of recovery), careful weight management should not be an afterthought.  

Here, Memorial Sloan Kettering registered dietitian/nutritionists Christina Stella and Suzanne Gerdes share tips on how to best manage weight and diet during and after cancer treatment.

Don’t restrict yourself to certain foods.

Chemotherapy and radiation treatments can cause a host of side effects that make it difficult or unpleasant to eat, including nausea, taste changes, and mouth sores, among other things. But many patients, as soon as they receive a cancer diagnosis, decide to restrict their diets in hopes of offsetting years of bad eating habits, Ms. Stella explains.

“All of a sudden they’re going vegetarian, saying they’ll never eat sugar again, or everything has to be organic,” she says. “But they don’t know how chemo or radiation will affect them, and then they start struggling. It’s not a good idea to restrict your diet when treatment already cuts down on what you’ll want or be able to eat.”

“Research suggests that eating a variety of foods is better for your health,” Ms. Gerdes adds. “Unless your doctor advises you to avoid specific foods for medical reasons, you should not restrict certain foods or nutrients, since they may not change the course of your cancer.”

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On some days, it’s enough to just eat.


Ideally, Ms. Stella explains, patients currently undergoing treatment will use a modified version of the USDA’s MyPlate icon to guide their nutritional intake. But instead of splitting the plate down the middle — with protein and carbohydrates occupying one side and fruits and vegetables on the other — these patients should aim for a “peace sign” consisting of equal portions of fruits and vegetables, carbohydrates, and lean protein. It’s beneficial for cancer patients to increase the amount of protein they eat, since adequate protein intake is particularly important to avoid losing lean muscle mass when dropping weight.

This goal changes, however, when patients don’t feel well enough to eat much of anything.

“For those having difficulty maintaining their weight, it can get to the point where any calorie is really more important than being picky about food choice,” Ms. Stella says. “Too much concern about types of food can give the patient a lot of anxiety. Just eat.”

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Stay hydrated.

Staying hydrated is important for all cancer patients to help their bodies deal with the effects of treatment. But for those trying to stem weight loss, it’s also an opportunity to add calories to their diet in a taste-friendly way. 

“If our goal is to add calories when hydration becomes more important, then why not combine both?” Ms. Stella asks.

“Water and drinks with calories, like 100 percent fruit juice, do the same thing,” Ms. Gerdes adds. “They keep you hydrated.”

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Keep as active as possible.

Fatigue is such a prevalent side effect of many cancer treatments that patients may find it difficult to get off the couch on some days, much less head outside for a walk. But staying physically active is important for weight management regardless of whether weight loss or gain is desired because regular movement helps maintain lean muscle mass.

“We really want patients to hold on to their muscle mass because research has told us there are poorer prognoses for patients who lose their lean body mass at a very rapid rate,” Ms. Stella says.

If you’re looking for a class, take a look at the fitness and yoga classes on offer at MSK’s Bendheim Integrative Medicine Center. Anyone can join.

Integrative Medicine at Home
Learn about our array of mind-body wellness classes, available to enjoy from home.
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Put the brakes on supplement use.

Eating whole foods, and getting the nutrients your body needs from them, is the gold standard of nutrition. In fact, vitamins and other supplements — which aren’t regulated by the US Food and Drug Administration or any agency — can actually interfere with certain cancer treatments and medications.

Vitamins and other supplements can actually interfere with certain cancer treatments and medications.

“It depends on what treatment you’re on and what supplement you’re taking,” Ms. Gerdes says, “but supplements are definitely something we want our patients to avoid most of the time because they’re taking so many medications, we don’t know what’s going to interact with them.”

Be honest with your medical team about vitamins or herbal supplements you’ve been taking in any form, whether pills, shakes, or powders. To educate yourself on herbs and potential adverse reactions or interactions with treatment, visit MSK’s About Herbs webpage.

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If you’re overweight, aim for controlled weight loss.

With two-thirds of the American population classified as overweight or obese, many newly diagnosed cancer patients who fall into those categories consider the prospect of treatment-related weight loss to be a silver lining. But it’s not your ticket to become the Biggest Loser, Ms. Stella and Ms. Gerdes say.

“We want to make sure they’re not losing in an uncontrolled manner,” Ms. Gerdes says, noting that rapid weight loss usually involves the loss of lean muscle mass, which is needed to maintain strength. “Losing five to six pounds a week would be concerning.”  

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Use apps to keep track.

Since many patients already carry smartphones everywhere, Ms. Gerdes and Ms. Stella recommend using apps such as MyFitnessPal to keep an online food journal, tracking not only calorie intake and activity levels but also types of calories consumed.

“It’s a good visual for them, telling them how many carbs they’re getting compared to protein,” Ms. Stella says. “Since we’re always stressing protein, it really helps them see what foods are contributing to that and how they can improve their diet.”

“We only use mobile apps for weight loss,” she adds. “Using MyFitnessPal or mobile tracking devices are like having a dietitian with you at all times. It lets us know where a patient can make changes to their diet to eat fewer calories — which is the goal of tracking.”

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After treatment, be prepared for change.

The end of treatment brings pivotal changes, both mental and physical, for cancer survivors, including a recommended switch back to a mostly plant-based diet to manage their weight. Just like other healthy people, survivors should follow the MyPlate recommendations to fill half their plates with fruits and vegetables and split the remaining half between grains and protein.

“For survivors, it’s still very important to make sure their weight is a healthy weight,” Ms. Gerdes says, explaining that this group may be at higher risk for other health conditions, including type 2 diabetes and heart disease. “We want to make sure that once they’ve gotten over the hump of treatment that they continue forward with a healthy diet, at a healthy weight, with a healthy lifestyle.”

Ms. Stella adds: “Recommendations about weight management are patient specific, and there is no meal plan that’s right for everyone. Patients undergoing active treatment will always be instructed to maintain or gain weight, while some survivors may be instructed to lose weight. It’s always best to check with your primary doctor to determine if weight loss, gain, or maintenance is best.”

Recipes for People with Cancer
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Commenting is disabled for this blog post.

As a chinese, Can I go to MSK to treat lung cancer? If so, what shall I do before live in MSK? and the charge estimate ? Thanks

Dear Jason, we are sorry to hear about your diagnosis. We welcome patients from all over the world through our International Center. To learn more about our services for patients from other countries, please visit https://www.mskcc.org/experience/become-patient/international-patients. The staff at our International Center would be happy to provide more information about arranging for you to meet with one of our specialists. Please email them directly at international@mskcc.org. Thank you for reaching out to us.

My husband has advanced cancer. He's gone through all the above side effects of cancer and chemo. We've learned that his cea has gone up
again. Our concern is his weight. We are trying to balance out, however, I'm concerned about the reaction of sugars in reference to the spreading of cancer. What is your suggestion?
Would you suggest the Alkaline diet? His Oncologist has told him not to drink herb tea's etc. that it actually interferers with the chemo's 'Job'. Please if you know how we can work on this CEA to lower the levels, share this info with me. Thank you.

Dear Florence,
We are unable to offer specific medical advice on our blog. However, here is what MSK experts say in general about diets:

“There is currently not enough evidence to recommend ketogenic diets (or any other specific diet) as a mechanism for cancer prevention or treatment. However, there is evidence to support the health benefits (including cancer prevention and cancer outcome) of avoiding metabolic syndrome, diabetes and/or obesity via healthy lifestyle choices.

Patients with advanced cancer may face a challenging situation in terms of adequate caloric intake and, thus, restrictive diets are often not advisable. At this point, it is reasonable for cancer patients to follow a healthy diet with a variety in nutrient composition, and for those not in a state of caloric deficit to avoid foods with excess added sugars or refined foods with low nutrient content (“junk foods”).

Each patient’s nutritional needs are different, depending on his/her health conditions. There is no universal diet that is good for everyone. Patients should discuss their nutritional needs with their health care professionals.”

Thank you for your comment.

My concern is that since my last chemo treatment on April 18, 2016, I have gained weight. And it seems to me as if there is no end to it. I walk daily as a form of exercise, eat the same as before my treatment ended, but keep gaining weight. What can I do?

Joanna, we recommend you discuss this with your healthcare team. Some of your medications may be causing the weight gain, or there may be other underlying causes. Thank you for your comment.

I have neck cancer and went thru 7 weeks of chemo (once a week cituxamab) and 33 radiation treatments. I am having a tough time maintaining weigh due to lose of appetite. I can swallow and a couple of mouth sores that aren't bad. I was drinking Boost however it started bothering my stomach. I have switched to Carnation instant. Any other suggestions? Does appetite come back at some point? When??

Hi, Joe, we are sorry to hear about your diagnosis and the loss of appetite you are experiencing. If you are an MSK patient, you may be interested in making an appointment with one of our nutritionists for a consultation and suggestions on how to improve your appetite and help with your mouth sores. They can be reached at 212-639-7312.

We also have some good patient education materials that offer some helpful tips on coping with these issues:

Mouth Care During Your Cancer Treatment

Eating Well During and After Your Cancer Treatment (includes menu ideas and recipes for people with special dietary needs)

Please follow up with your doctor to see when you might expect to regain your appetite or if you continue to lose weight. Everyone is unique in their experience with recovery. We hope this is helpful and wish you well as you continue to recover from your treatment. Thank you for reaching out to us.

I have had one session of immunotherapy which I'm excited about. Pemetrexed ran it's course a while ago.
I find I don't like textures of various foods which tends to change daily. I'm now at 96 lbs at 5'4" and would like to gain weight. I'm taking a plant based protein supplement but know I need more. How can I gain weight.

Dear Carol, your oncologist or nurse may have some good suggestions for you, but you may also find it helpful to read through our patient education materials on “Eating Well During and After Cancer Treatment,” which can be found here: https://www.mskcc.org/cancer-care/patient-education/eating-well-during-…
It includes suggested menus for people with special dietary needs (such as those who need to gain weight) and even sample recipes. We recommend that you to discuss any specific questions about your particular nutritional needs with your doctor. Thank you for reaching out to us.

I've had ovarian cancer and after surgery and during chemo I lost weight now that I'm recovering I'm gaining fast but I do not want to continue to be obese,especially health wise,certain grain foods and vegetables cause me to bloat and it also runs me to the bathroom (IBS),how can I lose this weight,I've just finished physical therapy sessions so now I'm afraid to overdue myself to lose the pounds....please help

Dear Kaamilya, your oncologist or nurse may have some good suggestions for you, but you may also find it helpful to read through our patient education materials on “Eating Well During and After Cancer Treatment,” which can be found here: https://www.mskcc.org/cancer-care/patient-education/eating-well-during-…
It includes suggested menus for people with special dietary needs (such as those who are trying to maintain or lose weight) and even sample recipes. We recommend that you to discuss any specific questions about your particular nutritional needs with your doctor. Thank you for reaching out to us.

great read! thanks for this

Glad you found this information helpful, Rose Ann!

currently a patient in forth month of ,horrible diarrhea....really need some help

Dear Samuel, we are sorry to hear about the side effect you are experiencing. We recommend that you report this to your doctor for appropriate follow-up and care. Thank you for reaching out to us.

Hi I have been losing weight at a fast pace. I've been drinking shakes, ice cream etc. i had seen another post related to nutrition on msk can't find it. It had a section that had supplement shakes. Can you suggest anything

Dear Dorine, we recommend you discuss this with your healthcare team. Thank you for your comment, and best wishes to you.

My wife was diagnosed with pancreatic cancer about 1 month ago. She is being treated at the Massachusetts General Hospital. She has had one chemo treatment and is scheduled for the next on the 27th of April. She is also on Humalog and Lanthus for diabetes. During her diagnosis, two stents were placed in her bile ducts. She is now experiencing lots of gas and hunger. These issues will be discussed when we meet with her oncologist next week.

Dear Guy, we’re sorry to hear your wife is going through this. Thank you for sharing your story. Best wishes to you and your family.

My wife,63 years old,height 5 ft 3 inches,currently 67 kg,is a CML patient for three years. She has also hypertension and dyslipidemia which is under control. Her doctor insists on weight loss by ten kg. She actually eats very little.Please suggest tips about dieting. Also, please advise whether weight loss is abosolutely necessary. Her weight before start of treatment was 63 kg.

Dear Safdar, we’re sorry to hear about your wife’s CML diagnosis. We recommend that she discuss this with her healthcare team, or ask them for a referral to a nutritionist who has experience working with cancer patients. Thank you for your comment, and best wishes to you and your wife.

I was diagnosed with late stage 2 , triple positive breast cancer with lymph node involvement earlier this year. Since then I have gone through a FEC-D chemo regimen and five weeks of daily radiation. I will continue to receive tri-weekly Herceptin infusions until late August. To date I have lost 10kg. Will this weight loss be maintained or should I expect weight gain after starting Tamoxifen?

Dear Amanda, we’re sorry to hear about your diagnosis. Weight gain is a common side effect from taking tamoxifen. We recommend that you discuss your concerns with your medical team. Thank you for your comment, and best wishes to you.

I am a 65 year old male undergoing treatment for Multiple Myeloma. I am three fourths of the way through my chemotherapy and I am losing significant muscle mass. I also have Type II Diabetes.
I would dearly love to know a diet to keep up my weight to existing levels while taking care of my diabetic restrictions on food.

Dear Hassan, we’re sorry to hear you’re going through this. We recommend that you ask your oncologist for a referral to a dietician who specializes in working with people who have cancer.

Thank you for your comment, and best wishes to you.

My friend was told not to eat plant based when you are on immunotherapy for glioblastoma
-shouldn't she be eating some vegetables and fruit?!

Dear Ellen, we are not able to offer medical advice on our blog. We recommend that your friend discuss this with her doctor or with a dietician who is familiar with her medical history. Thank you for your comment, and best wishes to you and your friend.

Diet and exercise has become the focus for many people’s weight loss attempts. For some people this approach provides results and for a few, these results can be maintained long-term. For most people, however, long-term success with diet and exercise alone is rare and for these folks, greater success is usually seen after they become involved with a medical weight loss team.

My mother has completed her 6 months of chemo for colon cance. ashe lost 10 pounds in a week of her surgery and the didn't eat much so she continued to loose weight throughout the treatment. now she id 2 months post chemo and she is gaining weigh around her stomach area. Is this normal? or a sign of something??

Dear Alison, we’re sorry to hear your mother has been through this. We recommend that she discuss her concerns with her healthcare team. Thank you for your comment and best wishes to both of you.

My mum has had cancer. And she went through chemo, had her breasts removed ovaries taken and limb notes. It’s been over 5 years she’s in the clear. She wants to loose weight but find that nothing is improving as she has done many of the diets are around. I don’t think she has thought of this but is because she has had her limb notes removed she’s not loosing any weight. I really would like to help if u can suggest anything I would really appreciate it

Dear Suziye, we recommend that your mom reach out to a nutritionist who has experience working with cancer survivors. Her oncologist may have recommendations. Thank you for your comment, and best wishes to you and your mom.

I was diagnosed with stage 4 squamous non small cell lung cancer 3 months ago. I am lucky in the sense that it only metastasized to my skull. I’ve had that tumor removed and my right upper lobe of my lung. I am currently tumor free. I hVe just completed 10 radiation treatments to my head and start chemo in two days. My chemo drugs are Carboplatin and Gemzar. Can you tell me if these chemo drugs typically make patients gain weight. I am currently at a healthy weight . I am 54 years old, 5’4” and a 127 lbs. I work hard to maintain a healthy weight as I was heavier most of my life. I e maintained this weight within 5 lbs for the last five years and am very concerned about weight gain. I know you can’t tell me for sure as everyone is different but can you tell me statistically. Do most people lose or gain weight on this regimen. I will be doing 4 cycles. Once a week for two weeks then an off week. Thank you in advance !

Dear Patricia, we’re sorry to hear about your diagnosis, but glad to hear that you’re currently cancer free. We recommend that you discuss your concerns with your cancer doctors. If you do experience weight gain, they may be able to refer you to a nutritionist who specializes in working with people who have cancer. Thank you for your comment and best wishes to you.

Thanks for the article, being a vegetarian I am getting used to the idea I may need to supplement diet with shakes or powders, I am trying ISOPURE just to get used to the taste of them, I am also a but worried with keeping my weight stable since I never really needed outside (powder or shakes) before and especially during the upcoming treatments, and will take advantage of the help MSK can offer

I am losing weight rapidly as i have no appetite for any food substance. I have a heavy salty taste in my mouth all the time and can’t get rid of it. Please help, i don’t want to be fed through the nose, I must find a way to eat.thanks.

Dear Lex, we’re sorry to hear you’re going through this. We recommend that you speak with your doctor or nurse about your situation. Thank you for your comment and best wishes to you.

I was overweight when I was diagnosed with squamous cell carcinoma in neck. I was up to 325 lbs at 52 years old. I am a big guy and could always carry weight and be active with no problems. But it got out of hand and increased rapidly over 18 months. I felt terrible so I did something about it. I started a keto/Atkins type diet and lost 20 lbs in 40 days then it started to slow down. But I felt much better! So after diagnosis I am now in radiation and chemo. Chemo once a week (Cisplatin) and radiation 5 times a week for 33 treatments. They told me stop keto and to maintain my weight but I feel terrible. So I started eating calories the recommended and gained 8 pounds. Felt bad and lethargic. Next week I lost 6 pounds somehow. I guess the treatment. Still feel lethargic. Can I take in the calories healthily and exercise and continue to lose weight slowly during chemo and radiation if I am obese?

Dear George, we recommend that you discuss this with your medical care team. Thank you for your comment and best wishes to you.