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  • Writer's pictureSurviving Breast Cancer

Metabolic Changes After A Breast Cancer Diagnosis

Updated: Aug 21, 2023

By Stacey Devine, MD

Many women gain weight or increase in body fat percentage after a breast cancer diagnosis. These metabolic changes increase the risk of recurrence and other complications like diabetes and heart disease. Understanding why this happens can help you make lifestyle changes to support your health. Continue reading to learn about various factors that can contribute to weight gain during and after breast cancer treatment, and what you can do to address them.

How does breast cancer treatment cause weight gain?

Breast cancer treatments themselves may contribute to weight gain and changes in body composition. Women who receive chemotherapy have an increased risk of weight gain and metabolic dysfunction. Studies on weight gain from hormone-blocking medications like tamoxifen and aromatase inhibitors are mixed. However, a recent study found that women who have more side effects from these medications are at an increased risk of weight gain. Joint pain from aromatase inhibitors can make exercise more difficult. Many cancer treatments are believed to negatively impact the gut microbiome which can also increase weight gain.

How treatment side effects can impact your weight

Side effects during treatment can impact weight gain and metabolic changes, and therefore need to be addressed more fully. Fatigue makes participating in physical activities more challenging. Sleep-disrupting hot flashes and insomnia are common in breast cancer survivors. Poor sleep can impact hormones like leptin and ghrelin, which impact food cravings and hunger cues. Sleep issues and chronic stress from a cancer diagnosis can also increase cortisol levels. Cortisol can increase insulin, decrease metabolism, and increase the storage of visceral fat in the belly.

What can you do about these changes?

Breast cancer survivors need to understand the risk of these metabolic changes for their health. They also need support to adopt a proactive approach and maintain their overall well-being. Here are a few practical tips to help you manage weight gain and a healthier lifestyle throughout survivorship.

Engage in regular physical activity: Even if you are in active treatment, try to move your body daily. You may need to lower your intensity or do shorter length sessions, but even some movement is beneficial. Patients who exercise regularly typically tolerate their treatments better.

Stay hydrated: Drink plenty of water throughout the day. Our bodies can confuse thirst with hunger, and staying well hydrated can reduce cravings and support your metabolism. Avoid sugary drinks, as these can easily add hundreds of calories a day to your diet and have no nutritional value.

Incorporate balanced meals: Include a mix of protein, healthy fats, whole grains, and an abundance of vegetables and fruits. Try to get the majority of your diet from whole food sources to make sure you are getting plenty of essential nutrients.

Prioritize quality sleep: Set yourself up for success with a relaxing bedtime routine to promote better sleep habits. Keep your bedroom dark, cool, and quiet to facilitate deep sleep.

Manage stress: techniques like meditation, breathing exercises, journaling, and spending time in nature can all help reduce stress and stress hormones.

If side effects from your treatments are not relieved by lifestyle measures and are negatively impacting your quality of life, consider an integrative oncology consultation. Integrative oncology providers are trained to help patients with cancer reduce side effects from their treatments and improve their quality of life.

Many of the factors contributing to weight gain may be outside of your control. However, you have the power to take control of your well-being and make positive changes to support your health journey. By focusing on what you can control and your lifestyle choices, you can build a strong foundation for a healthier life after breast cancer treatment.

Learn more:

On the Podcast: Breast Cancer Conversations

Diet, Exercise, and a Breast Cancer Vaccine, Oh My! With Judith Fitzgerald

Metabolic Health and Breast Cancer Brings Clinical Trials for TNBC and MBC Patients

What You Need To Know About Your Metabolic Health and Breast Cancer Resources & Support:

Submit Your Writing: SBC Blog Submissions

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