Skip to Content

How your weight affects your cancer risk

Focused on Health - August 2014

by Markham Heid

Maintaining a healthy weight is one of the best things you can do for your overall health and to lower your cancer risk. But finding your healthy weight in a chart and obsessively checking the number on the scale doesn’t paint an accurate picture.body weight

When it comes to your weight, what matters is the amount of body fat you’re carrying around – and where.

“We used to think fat cells were just for storing energy,” says Stephanie Maxson, senior clinical dietician in MD Anderson’s Integrative Medicine Center. “But fat cells are actually metabolically active. That means they produce hormones and other chemicals that affect your body’s immune system and its ability to fight off disease.”

A higher weight on the scale may indicate that you have more body fat than recommended. And, a higher percentage of body fat puts you at greater risk for cancer, heart disease and diabetes. “In particular, the fat around your waist can disrupt your hormones,” Maxson says. This increases your chances of developing breast and uterine cancers.

Carrying too much extra weight also can put stress on your back and joints. This added pressure could leave you with aches and pains, causing you to be less active and gain more weight.

Luckily, you can take actions to manage your weight and reduce your body fat. Maxson offers this advice.

Know what causes high body fatmeasure body fat

Maxson says a handful of factors can contribute to your weight:

  • Your diet. In general, taking in more calories than your body burns will lead to weight gain. 
  • Your activity levels. The more you move, the more energy your body burns, and the more likely you can keep your weight within a healthy range.
  • Your genes. Genetics plays a big role in your body shape as well as your metabolism, which is your body’s ability to burn calories.
  • Your age. Your metabolism tends to slow down as you age, meaning it can be harder to stay trim as you grow older. Hormonal changes and lack of exercise also contribute to age-related weight gain.
  • Your health. Some illnesses sap your energy, which can prevent you from staying physically active. Certain diseases and their accompanying medications also can lead to an increased appetite and greater body fat storage. Ask your doctor if your medical condition may be a factor.

Measure your body fat

“Unfortunately, there’s no simple way to find out your exact body-fat percentage without expensive tools or your doctor’s help,” Maxson says. Your age and gender also are important factors for determining your target body fat range.

If you’re not willing to wait for your next physical, you can measure your waist circumference at home for a rough gauge of your disease risk, Maxson says. (Use our step-by-step guide to measure your waist.)

She also cautions against using only body mass index (BMI) to assess your health.

BMI is calculated using only two pieces of information: Your height and your weight. “This is overly simplistic and tends to overestimate body fat among athletes or muscular people, while underestimating body fat among the elderly or those with diseases,” Maxson says. “Your best measure is your doctor.”

Take steps to slim downexercise and weight

Ready to get lean? “Focus on diet and exercise. Those are the two most important factors,” Maxson says.   

Exercise. Whether you’re running or gardening, lifting weights or brisk walking around your neighborhood, physical activity burns calories and fat to help you stay lean.

Aim for at least two-and-a-half hours of moderate exercise or one hour and 15 minutes of more vigorous exercise each week to reduce your chances for cancer. Use our training guide to get started.

Eat right. Maxson recommends following these healthy diet rules:

  1. At mealtimes, fill half your plate with fruits and non-starchy vegetables to get the vitamins, minerals and phytonutrients that help protect you from diseases like cancer. The fiber will help you feel full and avoid weight issues.  
  2. Devote another quarter of your plate to lean protein like beans, lentils, baked fish, and skinless chicken or turkey. You’ll get important nutrients while helping you stay full.
  3. Limit starchy vegetables like potatoes, corn and green peas, which can raise your blood sugar levels and trigger the storage of fat cells. If you’re going to eat these foods, choose colorful starches like sweet potatoes or yellow corn.
  4. Avoid processed grains like crackers, chips, cookies and breakfast cereals. They tend to be stripped of fiber. Instead, choose fiber-packed whole grains like brown rice, quinoa and buckwheat. 

Don’t be discouraged if you fail to see results on your bathroom scale. “Even if your weight stays roughly the same, your body should feel healthier as your weight shifts away from your danger zones,” Maxson says. “Plus, you’ll lower your disease risk, and raise your energy and mood levels.”


© 2014 The University of Texas MD Anderson Cancer Center