Weight gain after breast cancer therapy: What can be done?

By Naveed Saleh, MD, MS | Medically reviewed by Jeffrey A. Bubis, DO, FACOI, FACP
Published January 19, 2023

Key Takeaways

  • Weight gain is frequent among women with breast cancer and often continues after cancer therapy ends.

  • This weight gain may lead to negative body image, distress, lowered vitality, and increased death rates among women with breast cancer.

  • Although most studies focus on weight loss following weight gain in those with breast cancer, preventive measures such as a size-acceptance weight management program may help.

A common issue among women with breast cancer is weight gain, which is particularly common among those who are normal weight/overweight, younger, or on chemotherapy.

As researchers study this issue, clinicians can help patients with breast cancer prevent weight gain by recommending such measures as seeing a dietician, changing their diet, and daily exercise. Programs to help them accept their size may also be helpful.

Causes of weight gain

Most breast cancer-related weight gain occurs during the first year after diagnosis. This weight gain typically increases during the duration of chemotherapy and continues after therapy ends. It outpaces the weight gain experienced with normal aging, according to research published by Supportive Care in Cancer.[]

Various factors could underlie weight gain in patients with breast cancer, including stress, the shock of a diagnosis, life disruptions, and lower levels of physical activity.

Consequences of increased weight

Weight gain can lead to negative body image and distress, as well as decreased vitality, impaired physical function, and other potential limitations.

Studies have demonstrated that weight gain following breast cancer diagnosis heightens the risk of all-cause mortality.

According to the Supportive Care in Cancer article, results of a Nurses’ Health Study demonstrated that weight gain after breast cancer diagnosis was correlated with higher rates of recurrence, breast cancer-related mortality, and total mortality in the following groups of women: never-smokers, those with tumors ≤ 2 cm, those with no nodal involvement, and those with a BMI < 25.

Prevalence of weight changes

Publishing in the International Journal of Epidemiology, European researchers reported the results of the European Prospective Investigation into Cancer and Nutrition (EPIC) study, which assessed the relationship between weight change from age 20 years until middle adulthood and breast cancer risk.[]

The investigators found that among 150,257 women (median age: 51 years) followed for an average of 14 years, there were 6,532 cases of breast cancer. Women who were lean at age 20 exhibited a positive correlation between long-term weight gain > 10 kg and postmenopausal breast cancer risk (HR = 1.42).

This association occurred regardless of hormone replacement therapy status and in patients with estrogen-and-progesterone-receptor-positive cancers.

Results of a cross-sectional survey done by Australian researchers and published in BMC Cancer indicated that among 270 respondents (mean age: 59.1 years), the number of women who were overweight or obese increased from 48.5% at diagnosis to 67.4% at the time of the survey.[]

Most of the women were White and diagnosed with stage 1–3 breast cancer (n = 254) or ductal carcinoma in situ (DCIS) (n = 33). In total, 63.7% reported they had gained weight following diagnosis, with a mean increase of 9.07 kg.

Targeting acceptance instead of weight

Typically, weight management studies on patients with breast cancer have explored the targeting of weight loss following weight gain.

But in a 2020 study documented in the Supportive Care in Cancer article, researchers from the University of Texas MD Anderson Cancer Center examined the effects of randomized behavioral weight-gain prevention intervention during neoadjuvant chemotherapy and assessed its effects on weight, waist circumference, and quality of life.

In this pilot study, the investigators found support for a size-acceptance weight management program, with participants in the intervention group experiencing greater drops in waist circumference, increased vitality scores, and greater satisfaction.

"The size acceptance approach to weight management has shown effectiveness at maintaining weight and improving cardiovascular risk factors and resonates well with middle-aged women."

 Basen-Engquist, et al., Supportive Care in Cancer

“It focuses on improving health through lifestyle change, and de-emphasizes weight loss,” the authors added.

Suggestions to patients

For patients with breast cancer who want to stop gaining weight, the American Cancer Society has provided the following advice to be given to patients at the physician’s discretion:[]

  • Meet with a dietitian

  • Cut back on sugar and opt for healthy, lower-calorie options

  • Limit fluid intake in those with edema

  • Limit salt intake

  • Portion control

  • Read food labels

  • Walk daily

As a measure of support, caregivers can weigh the patient at the same time daily and discuss their weight concerns and other issues with their cancer care team.

These measures may help women undergoing treatment for breast cancer to take off the weight—and keep it off—improving their well-being and quality of life.

What this means for you

Weight gain following breast cancer treatment may distress the patient and possibly impair their health and quality of life. Patients should be monitored for weight gain, and this effect of the disease and therapy should be targeted appropriately. Although the bulk of weight management involves interventions following weight gain, preventive strategies may also be beneficial.

Read Next: My journey with breast cancer—and my healthcare providers
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