I Have Diabetes and Cancer. What Can I Eat?

older male preparing a healthy meal for older woman.

A healthy meal plan can support your diabetes management and cancer treatment.

When you found out you had diabetes, you learned how to manage your blood sugar and follow a diabetes meal plan. But then a cancer diagnosis disrupted your diabetes management.

If you or a loved one faces this challenge, you are not alone. Nearly 1 in 5 people with cancer also has diabetes. Living with both can be challenging, especially when it comes to choosing what to eat.

Learn how cancer treatment can affect your blood sugar. Find healthy eating tips that can help you manage diabetes and get the nutrition you need during cancer treatment.

How Cancer Treatment Can Affect Your Blood Sugar

Chemotherapy, or chemo, is a common cancer treatment. Chemo helps kill or shrink cancer cells, but it also hurts some healthy cells. Damage to healthy cells can cause side effects, such as dry mouth, mouth sores, nausea, vomiting, and loss of appetite. These side effects can cause your blood sugar to drop too low because it may be hard to eat, or your body is not able to absorb what you’ve eaten.

Radiation therapy is another type of cancer treatment. This treatment kills cancer cells by using high-energy rays (similar to X-rays). Radiation therapy itself can spike your blood sugar because your body releases extra sugar to help cope with the treatment. This therapy also has side effects like tiredness. When feeling very tired, you may not be able to stick to your meal and activity plans that help manage diabetes.

Hormone therapy is often used to treat prostate and breast cancers. This treatment blocks cancer cells from getting the hormones they need to grow. But it can cause side effects, such as nausea and tiredness, which can affect your energy to stay physically active or eat nourishing meals.

In addition, other medicines used in your cancer treatment may affect your blood sugar. Steroids are often given with chemo to lessen nausea and vomiting. But the medicine can raise your blood sugar by making your body respond less effectively to insulin.

Despite these side effects, diabetes management doesn’t have to take a back seat to cancer treatment. In fact, managing blood sugar could benefit your cancer treatment by lowering the risk of getting infections. Here are healthy eating tips that can help you manage both conditions all together.

What to Eat When You Have Diabetes and Cancer

On days when you feel better, you can try a balanced meal plan that supports your diabetes management. This meal plan can also boost your energy throughout cancer treatment. But there may be times when you may not want to eat. It’s normal to have hard times, so don’t restrict your diet too much.

If you lose interest in eating or lose weight too quickly, talk to your diabetes health care team and cancer treatment team. If needed, you may want to try:

  • Foods that are higher in calories or protein but still healthy.
    It can be hard to eat a big meal when you lose your appetite. But enjoying high-calorie foods in small portions can give you the calories, protein, and nutrition you need to live with diabetes and fight cancer. For example, you can add avocado, olive oil, hard-boiled eggs, beans, or peas to your meal, or add nuts or seeds to a salad. You can even try high-protein milk or yogurt.
  • Foods that improve your appetite.
    Foods that are naturally sweet, such as bananas and nut butter, may help stimulate your appetite. Bitter substances like lemon juice and vinegar can also improve your appetite by stimulating saliva production. You may want to add some spices and herbs to your food to perk up the taste. Their unique flavors may also help reduce the amount of salt you add to your dishes.
  • Foods that you enjoy. (And don’t be afraid to try new foods!)
    As you know, having diabetes doesn’t mean you can’t enjoy your favorite foods. Eating the foods you like in moderation can keep you motivated during cancer treatment. Don’t be afraid to try some healthy foods you didn’t like before. Cancer treatment can change your taste, so perhaps you will find a new favorite!

How Can Caregivers Help?

If you are caring for a loved one with diabetes and cancer, you play an important role in helping them eat well. Giving care and preparing meals during this time can be a challenge. Here are steps you can take to overcome the challenge.

  • Take notes to keep track of what your loved one eats and record their blood sugar levels. Share this record with their health care team to find a meal plan that supports both diabetes management and cancer treatment.
  • Prepare small meals throughout the day, if possible. Aim for five or six small meals rather than three large meals. Eating small portions slowly can help with loss of appetite and help prevent blood sugar spikes. Cooking meals in advance and freezing them can save you time and help avoid wasting food.
  • Keep healthy snacks, such as sliced apples with peanut butter, yogurt with berries, and whole-grain crackers, within your loved one’s reach.
  • Don’t blame yourself or your loved one if they have trouble eating. Even with your best efforts, your loved one may have trouble eating because of cancer treatment side effects, or they may be worried or upset. It’s not their fault if they don’t have an appetite. So don’t take it personally. Talk with their health care team about what you’re doing and where you may need help.

Living with both diabetes and cancer can be challenging, but you’re not alone. Ask your health care team how to manage both conditions at the same time. You may also want to ask your doctor for a referral to diabetes self-management education and support (DSMES).