Breast Cancer: Dietary Guidelines and Things to Remember

Managing weight gain after diagnosis and treatment

People often gain weight after their breast cancer diagnosis and treatment. There are many reasons people might gain weight during or after treatment, including:

• Eating too many calories.
• Not being physically active.
• Starting menopause early.
• Having depression (strong feelings of sadness) and anxiety (strong feelings of worry or fear).
• Feeling hungrier than usual due to taking prescribed steroids.
• Eating for comfort or to deal with emotions.
• Eating more than usual due to side effects of treatment, such as fatigue (feeling more tired than usual) or nausea (feeling like you’re going to throw up).

If you’ve gained weight, it can be hard to lose it. Because of this, it’s important to try to stay at a healthy weight during your treatment.

Use the guidelines below to help avoid gaining weight. Work with your clinical dietitian nutritionist on your weight goals.

• Choose a balanced diet. Read the “Balancing your plate” section for helpful tips.
• Exercise regularly.
• Control your portion sizes.
• Always put food on a plate so you know how much you are eating. Don’t eat from a container or bag.
• Avoid eating while watching TV, during “screen time” (such as checking email or watching a movie), or while talking on the phone.
• Drink 8 (8-ounce) glasses of liquids per day. Choose water or other drinks without calories, such as seltzer.
• Don’t drink more than 1 cup of fruit juice per day. It’s better to eat whole fruit than drink juice.

You don’t have to change your diet all at once. You can set 1 or 2 goals each week. If you have setbacks, you can learn from them. Small changes add up to big results over time.

Balancing your plate

The balance of foods on your plate is important when trying to eat healthily. Two-thirds (or more) of your plate should be plant-based foods, such as vegetables, fruits, whole grains, and beans.

For your vegetables, try to choose non-starchy ones, such as:

• Broccoli.
• Cabbage.
• Cauliflower.
• Leafy greens, such as spinach, lettuce, kale, collards, and bok choy.
• Mushrooms.
• Asparagus.
• Zucchini.
• Peppers.
• Tomatoes.

Other healthy plant foods include:

• Whole grains, such as brown rice, whole-wheat pasta, quinoa, and barley.
• Starchy vegetables, such as potatoes, sweet potatoes, corn, pumpkin, and peas.
• Whole fruits, such as berries, apples, pears, kiwis, and oranges.

No more than one-third of your plate should be animal protein. Some sources of animal protein are:

• Fish, such as canned sardines, canned salmon, and fresh fish.
• Non-fat or low-fat dairy products, such as plain yogurt.
• Eggs.
• Poultry, such as chicken and turkey.

If you eat red meat, such as beef, pork, and lamb, try to eat it only once or twice a week.

You can also replace animal protein with plant proteins, such as beans, nuts, and tofu.

Your meal might not always look exactly like the plate shown here. You could have a cup of lentil and vegetable soup and a small apple, and you’d still get similar nutrients and have a balanced meal. You might also eat more vegetables at lunch and dinner than at breakfast. The most important things are to have a mostly plant-based diet and control your portions for all meals.

Managing portion sizes

A portion size is the amount of food you’re choosing to eat. A serving size is a standard amount of food and can sometimes represent the recommended amount of food.

It’s important to think about serving sizes when figuring out how much to eat. Portion sizes of bottled, packaged, and restaurant foods and drinks have gotten larger over the years. The table below lists the serving sizes of some foods.

Common measurements

Use measuring cups and spoons to measure your portions. Here are some common measurements that may be helpful to remember.

• 3 teaspoons = 1 tablespoon
• 4 tablespoons = ¼ cup
• 4 ounces = ½ cup
• 8 ounces = 1 cup
• 1 cup = ½ pint
• 2 cups = 1 pint

Understanding food labels

Reading and understanding food labels can help you make healthy food and drink choices. Food labels include information about the food or drink, such as:

• The amount of added sugars in 1 serving.
• The amount of vitamin D and potassium in 1 serving.
• The serving size.
• The number of calories in 1 serving.
• The percentage of the daily value for nutrients such as sodium, fiber, and vitamin D.

Figure 1. Food labels

How to read a food label

The label below lists the nutritional content of a ⅔ cup serving of macaroni and cheese (see Figure 1). The arrows point to the boxes on the right, which explain what each line means.

Keep a food diary

Tracking what you eat and drink with a written food diary helps you be more aware of your choices. It can improve your thought process and awareness of what, when, and why you eat. For example, you might find you eat too much late at night when you’re more tired than hungry. You might notice that you have certain snacks because you’re stressed or bored.

If you keep a food diary, you may be more likely to reach your nutrition and body weight goals. Keeping a food diary can also help you make better choices about the foods that you eat. Your clinical dietitian nutritionist can help you use your food diary to meet your nutrition goals.

To keep a good food diary, write down what you eat right after you eat it, including the portion size. Be as detailed as you can. For example, you can write that you ate “1 cup of bran flakes and ½ cup low-fat milk.” You can also include how you were feeling when you ate. See the sample food diary in the “Sample Food Diary” section for an example.

Many people find writing a food diary by hand with a pen and a small notebook works best. Other people use a smartphone app or the “Notes” section of their smartphone. You can choose any way that works best for you.

Planning a healthy diet

The guidelines below can help you plan a healthy diet. Work with your clinical dietitian nutritionist to find the diet that’s best for you.

Control your calories

• Control portion sizes at all meals and snacks.
• Eat mindfully. Check in with how hungry or full you feel before and after you eat.
• Avoid snacking. Eat your meals at set times during the day. Choose healthy snacks only if you need them.
• Avoid sweetened drinks, such as sodas and soft drinks.
• Limit how much alcohol you drink. Read the “Limit alcohol” section for more information.

Choose plant-based foods

• Vegetables, fruits, and other whole plant foods should be the largest part of your diet.
• Eat a wide variety of vegetables and fruits. Choose fruits and vegetables with different colors, such as dark green, purple, orange, yellow, red, and white, to get lots of different nutrients.
• Try to eat about 3 cups of vegetables and 1 to 2 cups of fruit each day.

Limit total and added sugars

Sugars are naturally found in many foods, such as fresh fruit and milk. It’s okay to eat naturally occurring sugars in moderate portions.

Some foods (such as soft drinks, fruit drinks, snacks, and sweets) have added sugars (sugars that aren’t found naturally). Foods and drinks with added sugars can add too many calories to your diet. Over time, this can make you overweight or obese. They can also cause issues with your blood sugar and insulin (a hormone that helps control your blood sugar levels). Insulin issues can include chronic hyperglycemia (high blood sugar), hyperinsulinemia (having too much insulin in your blood), and insulin resistance. These conditions may increase your risk for getting breast cancer and some other types of cancer. The World Health Organization (WHO) recommends having no more than 25 grams (6 teaspoons) of added sugar per day. This measure is for someone eating 2,000 calories a day.

Follow these recommendations to limit the amount of sugar you eat:

• Read food labels to find out how much added sugar a food or drink has.
  • Grams and % Daily Value are now required for added sugars. Less sugar is better.
  • Ingredients are listed in descending (decreasing) order. This means that the product has more of the ingredients that are listed first and less of those listed last. Make sure sugar isn’t one of the first few ingredients on the list.
  • Food labels list added sugars in many ways. Some names to watch for are:
    • Corn syrup.
    • Brown rice syrup.
    • High-fructose corn syrup.
    • Muscovado.
    • Fruit juice concentrate.
    • Maltose.
    • Dextrose.
    • Evaporated cane juice.
    • Turbinado sugar.
    • Sucrose.
    • Glucose.
    • Fructose.
    • Barley malt.
    • Raw sugar.
    • Honey.
    • Maple syrup.
    • Cane sugar.
    • Invert sugar.
• Save foods and drinks with more than 15 grams of sugar per serving for special occasions.
• Remember that sugar is sugar, whether it’s raw, brown, white, organic, or powdered.

If you have other health concerns, such as diabetes, prediabetes, insulin resistance, or obesity, talk with your clinical dietitian nutritionist.

Include fiber in your diet

Fiber is a part of plants that you can eat but can’t be digested by your body. Fiber is good for your health and can help you:

• Keep your blood sugar at the right levels.
• Lower your cholesterol levels.
• Have regular bowel movements (poop) and prevent constipation (having fewer bowel movements than usual).
• Feel fuller and more satisfied after a meal.

Most people should eat at least 25 to 35 grams of fiber per day. You can do this by eating about 2½ cups of vegetables or legumes, 2 cups of fruit, and 3 servings of whole grains every day. To eat 3 servings of whole grains, you could have 1½ cups of whole-grain cereal, oats, whole-wheat pasta, millet, quinoa, brown rice, or other cooked whole grains or 3 slices of whole-wheat bread.

Increasing the amount of fiber in your diet over a short period of time can cause gas and bloating. Add sources of fiber to your diet slowly and drink lots of water. This will help your body get used to the change.

Foods with fiber

High-fiber foods usually have at least 3 grams of fiber per serving. Vegetables, fruits, beans, and whole grains are usually high in fiber. They also have many vitamins and minerals. Whole grains include the entire grain seed. They’re better for you than refined grains. Examples of whole grains are:

• Brown rice, black rice, and wild rice.
• Spelt.
• Millet.
• Quinoa.
• Bulgur.
• Oats and oatmeal.
• Buckwheat.
• Barley.
• Whole wheat.
• Popcorn.

Read the labels on your foods to find those that are high in fiber. Labels that list the word “whole” or “whole grain” before the first ingredient are good fiber sources. For example, look for “whole wheat flour” as the first ingredient in bread, not just “wheat flour.”

Some foods such as yogurts and snack bars now contain added fiber (such as inulin). There isn’t enough evidence to suggest that these added fibers have the same health benefits as fiber that’s naturally found in foods.

The table below lists some good food sources of fiber. For more information and a full list of fiber-rich foods, read A Guide to High Fiber Foods.

Choose foods with healthy fats

It’s healthy and necessary to include some fat in your diet. There are different types of fat. Some are healthier than others.

Fat has a lot of calories. One gram of fat has 9 calories, while 1 gram of a carbohydrate or protein has 4 calories. This means that high-fat foods have a lot of calories in a small amount of food. This is important to remember if you’re trying to lose weight or stay at a healthy weight.

For people with certain medical conditions, limiting fat may be helpful. For most people, it’s better to avoid eating too many calories and choose healthier types of fats instead of avoiding them completely.

Saturated and trans fats

Saturated and trans fats may raise your cholesterol levels. High cholesterol is often linked to heart disease. Limit the amount of saturated and trans fats in your diet.

Saturated fats are naturally occurring fats. The following foods have lots of saturated fats:

• Meats, such as pork and beef.
• Full-fat dairy products, such as cheese and butter.
• Coconut, such as coconut oil and coconut milk.
• Palm oil.

Most of the saturated fat people eat come from foods like burgers, sandwiches, pizza, and desserts.

Trans fats aren’t naturally occurring. The Food and Drug Administration (FDA) has banned trans fats from many foods already, but you may still see them sometimes. Read the food label when buying packaged foods to see if the product has trans fats. Choose products with no trans fats whenever you can.

Trans fats are sometimes listed as “partially hydrogenated oil” or “fractionated oil.” Foods that may have trans fats include:

• Coffee creamers.
• Deep fried foods.
• Some margarines.
• Microwave popcorn.
• Processed or packaged cookies, cakes, chips, and crackers.

Monounsaturated and polyunsaturated fats

Monosaturated and polyunsaturated fats are healthier for you. They’re found mostly in plant foods, fish, and other seafood. Good sources of healthy fats include:

• Fish and other seafood, such as:
  • Salmon
  • Sardines
  • Halibut
  • Mussels
  • Cod
  • Herring
  • Anchovies
• Nuts, seeds, and oils, such as:
  • Almonds
  • Olive oil
  • Walnuts
  • Canola oil
  • Pumpkin seeds
  • Flaxseeds
• Vegetables and fruits, such as:
  • Avocados
  • Brussels sprouts
  • Bok choy (Chinese cabbage)
  • Seaweed

Limit alcohol

Research shows a link between drinking alcohol and an increased risk for breast cancer. Women who drink more than 1 serving of alcohol per day on average are at an increased risk of breast cancer. The type of alcoholic drink doesn’t matter. The risk increases with the more alcohol you drink. Drinking a lot of alcohol may also increase the risk of breast cancer in men.

Drinking too much alcohol is also linked to other health problems, such as:

• Liver disease.
• Cancers of the mouth, throat, and esophagus (the tube that carries food and liquids from your mouth to your stomach).
• Irritation of the stomach and pancreas (the gland that helps you digest food and controls blood sugar levels).
• High blood pressure.

If you drink, do it in moderation and try to save it for special occasions. Follow these tips to control how much alcohol you drink:

• Remember that different types of alcohol have different serving sizes. Below are the serving sizes for some alcoholic drinks. One serving of:
  • Wine or champagne: 4 to 5 ounces (about 100 calories).
  • Regular beer: 12 ounces (about 150 calories).
  • Hard liquor (such as tequila or vodka): 1.5 ounces (about 100 calories).
• Note the size of the wine glasses you use at home or in restaurants. Some wine glasses hold 20 ounces or more—up to 5 servings of wine.
• You can add things like seltzer to your alcohol to water it down so you don’t drink as much of it.

If you have any questions about alcohol, talk with your doctor, nurse, or clinical dietitian nutritionist.

Limit salt and sodium

Eating foods with a lot of salt can raise your blood pressure and increase your risk for stroke, heart failure, and kidney disease. Most people should eat less than 2,300 mg of sodium (about 1 teaspoon of salt) per day. Fresh food that isn’t processed is usually lower in sodium.

Read food labels to find out the amount of sodium in the product. Choose foods that are labeled “low sodium,” “very low sodium,” or “sodium-free.”

Follow these tips to reduce how much sodium you eat:

• When cooking, flavor your foods with fresh herbs and spices instead of salt.
• Limit the amount of canned foods you eat (such as canned soups).
• Limit the amount of packaged, processed, pickled, and cured foods you eat (such as pickles and deli meats).
• Don’t add salt to your food at the table.

About soy foods

Some breast cancer cells use estrogen and other hormones to grow. Because of this, many people have questions about soy foods and breast cancer.

Soy foods naturally contain plant compounds called isoflavones (i-so-FLAY-vones). Isoflavones are similar to the estrogen that’s made in our body, but they work differently. Eating soy foods (sometimes called phytoestrogens) won’t increase how much estrogen your body makes.

Research shows that eating whole soy foods won’t increase your risk of getting breast cancer. If you have breast cancer or have had it in the past, eating soy foods won’t make your cancer worse or increase your risk for cancer recurrence (when your cancer comes back).

Some research shows that eating soy foods may offer health benefits. This is still being researched.

It’s usually better to choose whole soy foods over very highly processed soy foods and ingredients. Whole soy foods contain important nutrients such as protein, iron, and calcium. Examples of whole soy foods include:

• Tofu
• Miso
• Tempeh
• Soy milk
• Edamame

You may also see soy ingredients in many foods, such as:

• Soy lecithin
• Soybean oil
• Soy sauce

These ingredients are safe for most people and won’t increase your cancer risk.

Some research shows that very high amounts of isoflavones may not be safe. It’s important to eat whole soy foods that may offer health benefits and not soy products in a supplement, powder, or pill form. Soy products marketed as dietary supplements may have health risks.

Eating well during your breast cancer treatment

There are many types of treatment for breast cancer. It’s important to eat well during your treatment. Eating well during your breast cancer treatment can help you:

• Feel stronger.
• Have more energy.
• Manage your side effects.
• Prevent or reduce weight gain or weight loss.
• Get the right nutrients.
• Lower your risk of foodborne illness (food poisoning).
• Avoid dehydration.
• Heal after surgery.

Eating guidelines for people getting chemotherapy treatment

Food safety

If you’re getting chemotherapy, you’re at an increased risk for getting an infection or foodborne illness. This is because chemotherapy treatment can lower the number of white blood cells in your body. These cells fight bacteria (germs) and keep your immune system strong. Avoid foods that aren’t prepared, stored, or handled correctly. This can happen where you shop for food, eat out, or even at home.

To prevent foodborne illness, it’s important to buy foods that are safe to eat and to make and store food safely. For more information, read Food Safety During Cancer Treatment.

Managing your body weight

During chemotherapy, some people gain weight, and other people lose weight. It’s best to try to stay at a healthy body weight and not gain or lose too much weight during treatment. For more information, see the section “Staying a healthy body weight.”

If you’re losing too much weight because of your chemotherapy treatment, you may want to change your diet. You may not be very hungry due to side effects of treatment such as fatigue, anxiety, and depression. If you lose your appetite (don’t feel as hungry as usual), follow the suggestions below:

• Eat your favorite foods.
• Eat small meals or snacks regularly during the day.
• Eat with friends or family that support you.
• Add healthy fats (such as olive oil, avocado, and nuts) to your meals and snacks.
• Ask for help buying and making food.
• Listen to music you enjoy while you eat.
• Plan meals on a set schedule so you don’t forget to eat.
• Try homemade smoothies with nutrient-rich ingredients such as fruits, vegetables, and nuts.
• Don’t force yourself to eat a large amount at once, but don’t skip meals entirely.

Read Eating Well During Your Cancer Treatment for more information about staying a healthy weight during your cancer treatment.

Staying hydrated

It’s important to stay well-hydrated during chemotherapy. Drink at least 8 (8-ounce) cups of water or other no-calorie or low-calorie drinks (such as seltzer or tea) each day.

Not drinking enough liquids can cause:

• Lightheadedness (feeling like you might faint).
• Dizziness.
• Nausea.
• Constipation.
• Fatigue.
• Urinary tract infections (UTI, an infection in your urinary system).

Try not to drink many sweetened drinks, soft drinks (such as cola or ginger ale), and juices.

Keeping up your energy

Fatigue is a common side effect during chemotherapy and may get worse over time. While there’s no one food to prevent or reduce fatigue, following a balanced diet, getting regular exercise, and getting enough sleep can help. You can also try the suggestions below.

• Limit the amount of added sugars you eat, such as candy, baked goods, and sodas. Too much added sugars and sweets can cause fatigue due to changes in blood sugar levels. They can also add too many calories to your diet.
• Try to have small, regularly spaced meals and eat protein-rich foods at each meal. Good sources of protein include nuts, nut butters, eggs, quinoa, beans and legumes, fish, plain yogurt, and lean poultry.
• It’s OK to have 1 or 2 cups of coffee or another caffeinated drink per day. Don’t have caffeine to stay up late or in place of balanced meals.
• If you feel tired during the day, try going for a short walk instead of eating if you’re not actually hungry.
• Limit or avoid alcoholic drinks.
• Stay hydrated.
• Try to be physically active.

Managing side effects

You may have different side effects during chemotherapy treatments. Side effects can be different for everyone. They can also be different every day. The following tables show some possible side effects during chemotherapy as well as foods you can try to help them and foods to avoid.

Nausea

Constipation

Diarrhea

Vomiting

Mouth sores

Taste changes or metallic taste

Heartburn

External resources

Academy of Nutrition and Dietetics
www.eatright.org
Has information about the latest nutrition guidelines and research and can help you find a clinical dietitian nutritionist in your area. The academy also publishes The Complete Food and Nutrition Guide, which has over 600 pages of food, nutrition, and health information.

American Cancer Society
800-227-2345
www.cancer.org
Has information on diet and other cancer-related topics.

American Council on Exercise (ACE)
888-825-3636
www.acefitness.org
Has information on a variety of health and fitness topics and can provide you with names of certified fitness professionals in your area.

American Heart Association
800-242-8721
www.heart.org/HEARTORG
Has information on healthy eating and general exercise guidelines. They also publish several heart-healthy cookbooks that can be found in most bookstores.

American Institute for Cancer Research
800-843-8114
www.aicr.org
Has information on diet and cancer prevention research and education.

BreastCancer.org
www.breastcancer.org
Has information on breast cancer treatment, diagnosis, day-to-day concerns, and how to lower your risk.

National Cancer Institute (NCI)
800-422-6237 (800-4-CANCER)
www.cancer.gov
Has information about cancer, including treatment guidelines, research news, clinical trial listings, links to medical literature, and more.

MSK support services
www.mskcc.org/cancer-care/outpatient/