Breast Cancer: Healthy Eating After a Diagnosis


Making healthy food and lifestyle choices after a breast cancer diagnosis is important for your overall health. It can protect against health problems such as heart disease, diabetes, osteoporosis and other cancers. It may also help lower the chance of breast cancer returning.

This handout provides healthy eating and lifestyle tips. If you are having problems eating, have had unplanned weight loss, or have side effects from chemotherapy or radiation treatments, the information in this handout may not meet your needs right now. Instead, speak with a registered dietitian to develop a custom food plan to meet your needs.

Steps You Can Take

Follow a balanced and varied diet rich in:

  • vegetables
  • fruits
  • whole grains
  • legumes.

This plant-based way of eating provides fibre and a variety of vitamins, minerals and other cancer-protective components. This type of eating helps you keep a healthy weight.

Fill half your plate with vegetables and fruit, one-quarter of your plate with whole grains, and one-quarter of your plate with legumes, fish, eggs or other meats. Examples of whole grains include oats, barley, whole grain whole wheat and quinoa. Legumes include soybeans, dried peas, beans, lentils and chickpeas. Eat legumes and soy foods instead of meat more often. If you like, add low fat milk and milk products.

Keep a healthy weight.
Being in a healthy weight range combined with healthy eating can lower the risk of developing new cancers and health problems like diabetes and heart disease. A healthy diet and an active lifestyle can help you manage your weight during and after breast cancer treatment. If you have concerns about excess weight or are underweight, talk to a registered dietitian.

Choose healthy fats.
Include small amounts of healthy fats every day. Healthy fats include:

  • Avocado, fish, especially oily fish like salmon, mackerel, herring and sardines, nuts and seeds
  • Oils such as olive or canola oil.

Use cooking methods such as broiling, steaming and roasting that do not need added fat.

Limit foods high in unhealthy (saturated) fat such as:

  • High fat milk and milk products (cheese, cream and ice cream)
  • Butter, palm or coconut oils
  • Skin on poultry
  • Fatty meats, including processed meat products like deli meats, sausages and bacon
  • High fat fast food, convenience food and processed foods such as chips and other snack foods, baked goods, French fries and deep fried foods

Choose smaller portions if you do eat these foods.

Limit foods with added sugar.
Foods high in added sugars are higher in calories, and eating them often may lead to weight gain. They are also usually low in nutrients that protect against cancer. To limit added sugars:

  • Drink water, unsweetened tea or coffee instead of sugary drinks like sweetened coffee and tea beverages, lemonade, fruit drinks, and pop or soda
  • Limit foods with added sugars such as sweetened cereals, baked goods, cake, donuts, candy and cookies.

Choose smaller portions if you do eat these foods.

Be active.
Physical activity can help you stay healthy and feel better during and after breast cancer treatment. It may also lower the risk of breast cancer returning. Combined with a healthy diet, it can help you reach and stay at a healthy weight.

  • Aim for at least 150 minutes (2½ hours) each week of moderate to vigorous activity that increases your heart and breathing rate. Add activities that you enjoy such as brisk walking, swimming or biking. Break activity into 10 to 15 minute sessions if needed.
  • It is helpful to include two strengthening activities, such as lifting weights, heavy yard work or using resistance bands each week.

While participating in physical activity is generally safe, check with your doctor or health care team to see what types and amounts of activities are best for you.

Get the recommended amount of calcium and vitamin D each day.
Some treatments for breast cancer can weaken your bones. Calcium and vitamin D are important nutrients for strong bones.

To get the recommended amount of calcium:

  • Eat or drink foods that are sources of calcium every day. Good sources of calcium include low fat milk (skim, 1%, 2%) and milk products (yogurt, kefir and cottage cheese) and calcium fortified soy or other plant-based beverages. When choosing milk products, choose low fat most often.
  • Talk to a dietitian before taking calcium supplements if you think you are not able to get enough from food and beverages.
Age Aim for Stay below (total from food and supplements)
19-50 years 1000 mg/day 2500 mg/day
Over 50 years 1200 mg/day 2000 mg/day

To get the recommended amount of vitamin D:

  • Eat or drink foods that are sources of vitamin D every day. Good sources include milk, fortified soy beverage and other plant-based beverages, and fatty fish.
  • If you are over the age of 50, a daily 400 IU vitamin D supplement is recommended in addition to eating food sources of vitamin D.
Age Aim for Stay below (total from food and supplements)
19-70 years 600 IU/day 4000 IU/day
Over 70 years 800 IU/day 4000 IU/day

Other Considerations:
Many women ask if specific foods or supplements should be included or avoided because of their effect on the growth of breast cancer. At this time, there is not enough research to say that eating any individual food or taking individual supplements changes the growth of breast cancer.

Commonly asked questions are answered below.

Soy and flaxseeds
Soybeans, soy foods (such as soy beverage, soy nuts, tofu, tempeh and edamame (green, young soybeans)) and ground flaxseed are a source of phytoestrogens. Phytoestrogens (or plant estrogens) are substances found in plants that are similar to the hormone estrogen. Past research in animals raised concerns that phytoestrogens in soy could stimulate the growth of breast cancer. Current research has found that eating soy foods is safe after a breast cancer diagnosis. Other plant foods may contain phytoestrogens, but in low amounts.

  • Soy products
    • One to two servings per day of soy can be included as part of a varied diet. A typical serving of soy is: 250 mL (1 cup) soy beverage, 125 mL (½ cup) tofu, 60 mL (¼ cup) roasted soy nuts, or 175 mL (¾ cup) edamame (young, green soybeans).
    • Avoid taking soy supplements, such as soy products in concentrated or pill form.
  • Flaxseed
    • Ground flaxseed, up to 15 to 30 mL (1 to 2 Tbsp) per day can be included as part of a varied diet. However, it may interfere with the absorption of some medications. Check with a pharmacist to see if ground flaxseed affects any medication you take.
    • Whole flaxseed is not a high source of phytoestrogens. Seeds generally pass through the gut without being broken down.

Milk and milk products: Some people are concerned about hormone levels that may be in milk and milk products. The use of growth promoting and milk producing hormones in dairy cows are banned in Canada. Low fat milk and milk products are a good source of calcium, vitamin D and protein and may be included as part of a healthy diet.

Alcohol: Drinking alcohol increases the risk for developing breast cancer. It is not known if drinking alcohol increases the risk of breast cancer returning. For cancer prevention, guidelines recommend women limit alcohol to no more than one drink per day or none at all.

One drink is equal to:

  • 341 mL (12 oz.) bottle of 5% beer, cider or cooler
  • 142 mL (5 oz.) of 12% wine
  • 43 mL (1.5 oz.) 40% spirits (e.g., rye, vodka, whisky, rum, gin).

Supplements: Taking individual herbal, vitamin and mineral supplements to prevent or treat breast cancer is not recommended. It is not clear if taking any supplement helps prevents breast cancer from getting worse or returning. There are concerns that supplements can interfere with cancer treatments or could have other unwanted effects. During cancer treatment taking a standard multivitamin mineral supplement is safe for most people.

Speak with a dietitian if you are worried that you are not getting enough vitamins and minerals from the foods you eat or if you have questions about supplements.

Additional Resources

For information and advice based on your specific food and nutrition needs and preferences, call 8-1-1 and ask to speak to a HealthLink BC dietitian.

For additional information, see the following resources:

Last updated: July 2018

These resources are provided as sources of additional information believed to be reliable and accurate at the time of publication and should not be considered an endorsement of any information, service, product or company.

Distributed by:

Dietitian Services at HealthLinkBC (formerly Dial-A-Dietitian), providing free nutrition information and resources for BC residents and health professionals. Go to Healthy Eating or call 8-1-1 (anywhere in BC). Interpreters are available in over 130 languages.

Is it an emergency?

If you or someone in your care has chest pains, difficulty breathing, or severe bleeding, it could be a life-threatening emergency. Call 9-1-1 or the local emergency number immediately.
If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.

Thanks to our partners and endorsers: