Weight loss


Weight loss during cancer treatment is common. It can sap your strength. It can also have an effect on your body image and self-esteem at a time when those things may already be affected by breast surgery, hair loss, or other treatment side effects. You may feel that weight loss is making you look sick and that it stops you from being able to keep the cancer private.

But there are ways to prevent or reverse weight loss that happens during breast cancer treatment.

What causes weight loss after a breast cancer diagnosis?

A breast cancer diagnosis comes with both medical and emotional changes that can impact your weight.

Many breast cancer treatments, including radiation therapy and medicines like chemotherapy, hormonal therapy and targeted therapy, can cause side effects that make it hard to eat healthy meals, or for you to want to eat at all. Nausea and vomiting, mouth sores and low appetite are all common side effects people treated for breast cancer experience. It’s understandable that someone going through these may have a hard time eating.

Breast cancer also has a strong impact on people emotionally. Many report feelings of depression, anxiety, extreme stress and mental fatigue as they cope with the disease and its impact on daily life. Loss of appetite is common with all of these emotional challenges, even in people without cancer. Simply being too tired or too busy to cook a decent meal can lead to weight loss.

How can I prevent or stop weight loss?

Though you may have seen images of much-too-skinny people with cancer in movies and TV shows, it’s actually less common for people with breast cancer to lose extreme amounts of weight during treatment today. This is largely because of improvements in preventing some of the side effects that make eating hard.

If breast cancer treatments are making you nauseous or causing you to vomit, tell your healthcare providers. They may be able to put you on anti-nausea medicine at the same time as you begin treatment to prevent these side effects. Anti-nausea medicines have helped many people with cancer avoid feeling sick or vomiting throughout their treatment.

If mouth sores are keeping you from eating, talk to your doctor about medicines that can help ease the pain they may be causing. You can also try these practical tips to choose foods that are less likely to make mouth sores feel worse.

It’s normal to feel a range of tough emotions after a breast cancer diagnosis, including sadness, anxiety and anger. But if stress or difficult emotions are getting in the way of your day-to-day life, and stopping you from doing basic things like eating, you may have a mood or anxiety disorder, like depression. Anxiety and depression are serious medical conditions that should be treated by a mental health professional. Talk to your healthcare providers. They should be able to recommend a mental health professional with experience treating people with cancer.

Some tips to maintain or raise your weight:

  • Choose calorie-dense foods like avocados, nut butters, creams, mayonnaise and oils. Cooking in rich oils such as coconut oil or avocado oil can greatly increase your calories per day.
  • It may be easier to drink, rather than eat, your calories if you feel nauseous. Try making a high-calorie, protein-heavy shake with supplemental drinks such as Ensure or Boost, ice cream, nut butters, protein powders and fruit.

Your healthcare providers can also connect you with a registered dietician, who can help you manage your weight and what you eat.


Reviewed and updated: June 9, 2017

Reviewed by: Christine Zoumas, MS, RD


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