Overweight and obese women — defined as having a BMI (body mass index) over 25 — have a higher risk of being diagnosed with breast cancer compared to women who maintain a healthy weight, especially after menopause. Being overweight also can increase the risk of the breast cancer coming back (recurrence) in women who have had the disease.
This higher risk is because fat cells make estrogen; extra fat cells mean more estrogen in the body, and estrogen can make hormone-receptor-positive breast cancers develop and grow.
Still, the link between extra weight and breast cancer is complicated and affected by other factors. For example, the location of the extra weight matters. Extra fat around your belly may increase risk more than the same amount of extra fat around your thighs or hips.
Steps you can take
Losing weight can be harder as you get older, but it can be done with careful changes to your diet and regular exercise. The first thing to do is to talk to your doctor about a healthy weight for you based on your age, height, body type, and activity level. Next, talk to your doctor about a safe and sensible plan to lose weight designed specifically for you and your needs.
Do you need to count calories?
Many people believe that if you eat fewer calories than you burn each day, you’ll lose weight, and if you eat the same number of calories that you’ll burn, you’ll maintain a healthy weight. This plan works for many people, but not all.
If you’re counting calories, it’s important to think about what you’re eating. Say Jane eats 1,200 calories a day of cake, cookies and white bread. She’s probably not going to lose any weight. Betty eats 1,200 calories a day of fresh vegetables and fruit and lean protein. She’s probably going to lose some weight and get a lot more nutrients from her food. Counting calories is only part of the weight loss equation.
And counting calories is only one way to lose weight. Because the hormone insulin plays a major role in how your body uses and stores fat, some research suggests that eating foods that keep insulin levels steady throughout the day — lean meat and fish, poultry, vegetables, and fruit — rather than foods like sugar, candy, white bread and crackers — can help you maintain a healthy weight.
Breastcancer.org Chief Medical Officer Marisa Weiss, M.D. says, "It can be hard to get enthusiastic about losing weight if you've had limited success in the past. Sometimes success can depend on how you think about losing weight: learn the steps that give you the biggest bang for your buck and reframe your feelings and attitudes about hurdles in your path. Here are just a few examples. You can turn progress into failure with a common misconception: eating and exercise are equally important for weight loss. In fact, 80% of weight loss is what you eat and drink. Only 20% relates to exercise. Don't get caught thinking they're 50/50 partners: a 400 calorie slice of cheesecake that takes 5 minutes (or less) to eat would take hours on the treadmill to burn off. You also have to be prepared to give up cooking methods that may be part of your family traditions (like deep-fried chicken or adding cheese to all your vegetables) and change old 'harmless' habits (like tasting while you cook or eating raw dough when you bake). It's important to be open to new foods, including those that you're sure you hate (like the tomatoes and fish you hated as a kid). Give them another chance as an adult. There are so many healthy options out there that will help you accomplish your goals. Once you get your game on, you'll feel so much better."
Create a healthy eating plan and an exercise plan. Once you have the OK from your doctor and a weight goal, you can create a healthy eating plan that meets your nutritional needs. You may want to talk to a registered dietitian about how to create a healthy eating plan that's tailored to your specific needs and likes.
If you're unable to work directly with a registered dietitian, you have some other options. Computer programs and online tools can help you further analyze what you eat. They go beyond whether or not you're getting enough of a specific nutrient. Some of them might even make recommendations about how much of specific foods you should eat per day and track your eating and nutrient patterns over time.
Exercise is such an important part of daily life that the United States Department of Agriculture said that all people should meet the Physical Activity Guidelines for Americans in the Appendix of the 2015-20 Dietary Guidelines for Americans. Regular exercise helps reduce breast cancer risk. And the American Cancer Society recommends that women who have been diagnosed with breast cancer exercise regularly (about 5 hours per week) to improve their quality of life and physical fitness, as well as to reduce the risk of developing new cancers. Research shows that women who exercise the equivalent of walking 3 to 5 hours per week at an average pace after being diagnosed with breast cancer may improve their chances of surviving the disease.
There's no magic bullet or single food that will make you lose weight quickly. In fact, the safest way to lose weight is to do it slowly — about a pound a week.
The United States Department of Agriculture 2015-20 Dietary Guidelines for Americans recommend:
getting less than 10% of calories per day from added sugars
getting less than 10% of calories per day from saturated fats
eating less than 2,300 mg per day of salt
The guidelines also recommend eating a variety of nutrient-dense foods across all food groups, including:
a variety of vegetables from all of the subgroups: dark green, red and orange, beans and peas, starchy, and others
fruits, especially whole fruits
grains, at least half of which are whole grains
fat-free or low-fat dairy, including milk, yogurt, cheese, and/or fortified soy beverages
a variety of protein foods, including seafood, lean meats and poultry, eggs, beans and peas, nuts, seeds, and soy products
Here are some tips to make your diet nutritious and help you lose weight:
Limit sugar, refined carbohydrates, and alcohol.
Eat small portions (no more than 6 to 7 ounces a day) of lean meat or poultry.
Remove the skin and fat from meat, poultry, and fish.
Cover your plate with fresh, nutrient-dense foods. Fill two-thirds of your plate with fresh vegetables, fruits, and whole grains, and one-third or less with meat and dairy products.
Eat lots of fruits, veggies, and whole grains. Eat at least 2 cups of fruit and 3 cups of vegetables each day and 3 ounces or more of whole grains. You will feel full longer and may be less tempted by junk food.
Choose non-fat milk and dairy products.
Go for variety. Buy a new fruit, vegetable, or whole-grain product each time you shop for groceries to keep from getting bored with your diet.
Drink water or drinks with no sugar added if you're hungry between meals. Avoid soda, lemonade, sweetened iced tea, and juices.
Keep healthy snacks on hand, such as:
salad with fat-free or low-fat dressing
carrot and celery sticks (organic is best)
bite-sized pieces of broccoli, cauliflower, or other vegetables
salsa with vegetables (not chips) for scooping
non-fat Greek or plain yogurt
low-fat cottage cheese
apple slices (organic is best)
unsweetened fruit tea or herbal tea
water with a slice of lemon or lime
broth or bouillon
Limit heavily salted, smoked, or pickled foods. They tend to have a lot of salt and nitrates.
Enjoy a salad with fat-free or low fat dressing before going out. It can curb your appetite and keep you from over-ordering.
Go in with a plan. Look at menus online before you go, and decide where and what to eat. Many chain restaurants offer healthy menu options that follow Weight Watchers or other eating plans.
Choose steamed, baked, or boiled vegetables, rather than those in sauces or with cheese.
Order meat/seafood that is steamed, broiled, roasted, or baked rather than pan-fried or deep-fried.
Ask for sauces, dressings, butter, and sour cream on the side so you can control how much you use. Or ask for your dish to be made without sauce or cheese.
Avoid casseroles. They often have sugary or salty sauces and lots of high-fat cheese.
Avoid or limit alcohol. Alcoholic beverages have no nutrients. And after you have one or two alcoholic drinks you may be more tempted to dive into the bread basket, order a plate of nachos, or sample something from the dessert cart.
Choose beverages without added sugar. A 12-ounce glass of regular soda pop has about 10 teaspoons of sugar per serving. Water has zero.
Order each item separately (a la carte), so you can get everything prepared how you want it, rather than ordering a combination plate with less flexibility.
Don't eat mindlessly. Ask the waitperson to remove the bowl of chips/bread/peanuts after you've had a small portion.
Don't order jumbo or super sizes.
Order an appetizer portion instead of a meal-size portion. Many restaurants offer the same dishes in both sections of the menu.
Wrap it up. Ask for half of your entree to be wrapped up to go when you order. Eat it for lunch the next day.
Share an entree with a friend and order an extra side salad with the dressing on the side.
For more information on healthy eating, dietary supplements, and nutrition resources, visit the Breastcancer.org Nutrition section.
— Last updated on June 29, 2022, 3:08 PM