Managing Weight Fluctuation During Cancer Treatment

Many patients with cancer expect hair loss, nausea and lack of energy that often accompany chemotherapy and radiation treatments. What may take them by surprise? Weight changes that can have deep physical and emotional effects.

“Weight loss can happen for multiple reasons,” says Kailey Proctor, MPH, RDN, Registered Dietician, The Center for Cancer Prevention and Treatment at St. Joseph Hospital in Orange, Calif. “Certain cancers cause patients to become hypermetabolic meaning their metabolism burns more calories throughout the day so they have a higher calorie requirement to maintain their weight. Often times the side effects of treatment cause weight loss.”

Weight gain in a patient going through treatment may be because the patient is tired from their treatment and is relying on calorie-dense foods, says Proctor.

“They might not have the energy to prepare homemade meals and are eating more frozen dinners or fast food for convenience,” she says. “The fatigue from treatment might cause the individual to be less physically active than they once were before their treatment started.”

The good news is that there are key strategies patients can undertake to maintain their weight during treatment, as well as coping mechanisms to enlist when dealing with weight gains and losses.

Keeping The Weight On – Or Off

For patients dealing with nausea and a lack of appetite, consuming small, protein-rich meals throughout the day can help keep the pounds on without having to eat a large plate of food in one sitting. Protein helps maintain lean body mass and may reduce some fatigue from treatment, says Proctor.

“By spreading meals throughout the day, the patient has more opportunities to get calories and protein where they might have missed out before,” she says Proctor. “These mini meals can be an apple with peanut butter, cheese and crackers, banana with peanut butter and yogurt or half a turkey sandwich. Including high-calorie foods, such as oils, butter, avocado, nuts, peanut butter, cheese and whole milk, to each meal provides the individual with calories to maintain their weight without increasing the volume of food they are eating.”

Other protein-rich foods include eggs, soy milk, edamame and tofu, and beans and legumes1.

Some patients may find even these small portions tough to get down. In that case, yogurt-based shakes and smoothies are a good bet, since “some patients with cancer find drinking liquids easier than eating and you can add a lot of calorie- and protein-rich foods this way.”

It’s also a good idea to stay hydrated by drinking plenty of water, fruit juice or sports drinks, or if that’s not doable, sucking on ice cubes. The University of Michigan Comprehensive Cancer Center suggests filling a two-liter container, or 64 ounces, with tap water each morning and taking small sips throughout the day so you can stay on top of how much you are consuming. Dehydration can cause one to lack energy and feel fatigued1.

If eating small meals and drinking frequently is a hurdle, Proctor suggests setting an alarm on your phone or watch to remind yourself to stay fueled.

What should be avoided? Empty-calorie foods such as candy, soda and baked goods that can give you a quick sugar rush, but result in a crash shortly after. 

For those dealing with weight gains, sticking to whole, unprocessed foods that are easy to grab, such as fruits, or fiber-rich whole grains and protein can increase satiety and keep energy levels up while keeping calories in check.

Sometimes thirst can mask itself as hunger; drinking the aforementioned 64 ounces of water a day can curb hunger and increase energy.

Patients taking steroids such as prednisone may experience fluid retention since these medications can cause the body to hold onto salt. Potassium-rich foods like bananas, kiwi and cantaloupe can help flush out sodium2.

Finally, while those dealing with weight gain might be tempted to diet, Proctor says this is a no-no.

“Now isn’t the time to follow a very restrictive diet because then the individual might miss out on good sources of calories and protein,” she says.

Talk to your doctor or healthcare provider about what types of foods and diet consideration may apply to you or your treatment.

Give Yourself a Break

While looking in the mirror and seeing weight changes can be upsetting to some patients, it’s important to avoid worrying too much about which foods or how much to eat, says Proctor. 

“It is important to keep in mind there will be some good days and some bad days,” she says. “However, being aware of any weight loss or gains and planning meals and snacks accordingly gives the patient and their family a sense of control over the situation. Meeting with a dietitian can also help manage the weight-related side effects of cancer treatment and give more individualized recommendations.”



1. A Healthy Boost. Michigan Medicine Comprehensive Cancer Center. Accessed January 3, 2018.

2. How Can I Avoid Gaining Weight During Cancer Treatment? Dana-Farber Cancer Institute. Accessed January 3, 2018.



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