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Diet, Exercise, and Your Cancer Risk

young family walks for exercise together along a river

Editor’s Note: Guidelines on diet and physical activity are updated as scientific evidence continues to evolve. Please read the most recent recommendations here.

Did you know that healthy eating and engaging in physical activity can lower your cancer risk? In fact, after quitting smoking, improving your diet and exercise habits are some of the most important things you can do to stay healthy.

American Cancer Society researchers estimate 18% of cancer cases and 16% of cancer deaths are related to a combination of eating poorly, drinking too much alcohol, not getting enough physical activity, and being overweight.

Top 8 tips for healthy eating

  1. Choose food in portions that help you get to and maintain a healthy weight. This downloadable card from the National Heart, Lung, and Blood Institute can help you estimate serving sizes.
  2. Eat at least 2½ cups of vegetables and fruits each day. Choose vegetables, whole fruit, and legumes such as peas and beans. Avoid adding creamy sauces, dressings, and dips.
  3. Drink more water and less sugar-sweetened beverages such as soft drinks, sports drinks, and fruit-flavored drinks.
  4. Choose fish, poultry, or beans instead of red meat (beef, pork, and lamb) and instead of processed meat (bacon, sausage, lunch meats, and hot dogs).
  5. Avoid calorie-dense foods such as French fries, potato and other chips, ice cream, doughnuts, and other sweets.
  6. Limit refined carbohydrate foods, including pastries, candy, sugar-sweetened breakfast cereals, and other high-sugar foods.
  7. Prepare meat, poultry, and fish by baking, broiling, or poaching rather than by frying or charbroiling.
  8. Choose whole-grain breads, pasta, and cereals (such as barley and oats) instead of breads, cereals, and pasta made from refined grains, and brown rice instead of white rice.

The role of alcohol

Drinking alcohol is linked to a higher risk of mouth and throat cancers, esophageal cancer, liver cancer, colorectal cancer, and breast cancer. Alcohol may also increase the risk of cancers of the pancreas and stomach. For each of these cancers, the more alcohol you drink, the higher your cancer risk.

For that reason, the American Cancer Society recommends limiting alcohol to no more than 1 drink per day for women and 2 for men. The recommended limit is lower for women because they tend to have a smaller body size and slower breakdown of alcohol than men.

A drink of alcohol is defined as:

  • 12 ounces of beer
  • 5 ounces of wine
  • 1½ ounces of hard liquor

Why physical activity matters

Being active can help improve your hormone levels and the way your immune system works. In addition to reducing your cancer risk, physical activity helps you reduce your risk of heart disease and diabetes, too.

The American Cancer Society recommends adults get at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity activity each week (or a combination), preferably spread throughout the week. This is over and above usual daily activities like using the stairs instead of the elevator at your office or doing housework.

For kids, the recommendation is at least 60 minutes of moderate- or vigorous-intensity activity each day, with vigorous-intensity activity occurring at least 3 days each week.

Moderate activities make you breathe as hard as you would during a brisk walk. This includes things like walking, biking, and gardening. Vigorous activities use your large muscle groups and make your heart beat faster, make you breathe faster and deeper, and make you sweat.

It’s also important to limit sedentary behavior such as sitting, lying down, watching television, or other forms of screen-based entertainment.

Controlling your weight

Another important reason to improve diet and exercise habits is that it helps you get to and stay at a healthy weight. Being overweight can increase cancer risk in many ways. One of the main ways is that excess weight causes the body to produce and circulate more estrogen and insulin, hormones that can stimulate cancer growth.

Being overweight or obese increases the risk of several cancers, including those of the breast (in women past menopause), colon and rectum, endometrium (the lining of the uterus), esophagus, pancreas, and kidney, among others. It also increases the risk of other chronic diseases, such as heart disease and diabetes.

One way to get an idea if you are at a healthy weight is to check your Body Mass Index (BMI), a number based on the relationship between your height and weight. Use our online BMI calculator to find out your number. To reduce cancer risk, most people need to keep their BMIs below 25, but there are some exceptions. Ask your doctor what your BMI number means and what action (if any) you should take.

For those who are overweight or obese, losing even a small amount of weight has health benefits and is a good place to start.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.