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Breast Cancer: Healthy Eating After a Diagnosis

Last updated: July 1, 2018
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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 and helps to support 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 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, and in combination with a healthy diet 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.



Aim for

Stay below (total from food and supplements)

19-50 years

1,000 mg/day

2,500 mg/day

Over 50 years

1,200 mg/day

2,000 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.

Vitamin D


Aim for

Stay below (total from food and supplements)

19-70 years

600 IU/day

4,000 IU/day

Over 70 years

800 IU/day

4,000 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 tofu and 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. Canada has banned the use of growth-promoting hormones and hormones that make cows produce more milk. 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.

Supplements: Taking individual herbal, vitamin and mineral supplements to specifically 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:

  • HealthLink BC – Get medically approved non-emergency health information.