Obesity and Cancer Risk

Aside from not smoking, staying a healthy weight throughout life is the single most important way to protect against cancer.

AICR's research has found a strong link between excess body fat and increased risk for cancers of the:

  • esophagus
  • pancreas
  • colon and rectum
  • endometrium
  • kidney
  • postmenopausal breast
  • gallbladder
  • ovarian
  • liver
  • prostate (advanced)
  • stomach 
  • mouth/larynx/pharynx

Body fat is a metabolically active organ.

Too much body fat can increase cancer risk in several ways:

  • Fat cells produce estrogen, and high levels of estrogen links to risk of some cancers.
  • Fat cells produce a variety of proteins that cause high levels of insulin and other hormones, which in turn may spur cancer cell growth.
  • Excess body fat produce cytokines and other substances that can lead to chronic inflammation, which links to increased cancer risk.

Research suggests that fat at the waist -- visceral fat -- is even more active in producing growth stimulants. So overweight people – particularly if they are apple-shaped – have high levels of substances circulating in their blood that stimulate cell division. The more often cells divide, the more opportunity there is for cancer to develop.

Because of the overwhelming evidence, AICR recommends maintaining a healthy weight throughout life to best reduce your chances of developing cancer. Read the full list of AICR’s Recommendations for Cancer Prevention.

Making changes for a healthy weight.

AICR experts stress that this potentially dangerous condition is preventable. At a time when two-thirds of Americans are overweight or obese, making changes to lower your cancer risk by preventing weight gain is more important than ever.

The following lifestyle modifications can help:

  • Avoid sugary drinks. Fill your plate with a variety of vegetables and other plant-based foods that can help fill you up while providing nutrients. Limit consumption of energy-dense fo
  • Limit the amount of high-fat, high-sugar foods you eat.
  • Be physically active for at least 30 minutes a day.