Body weight and cancer risk

Being overweight or obese is associated with a number of chronic diseases including type 2 diabetes and heart disease. Research also shows that being overweight or obese increases the risk of a number of cancers.

Excess body weight has been linked to 13 cancers by the International Agency for Research on Cancer (which is part of the World Health Organization). This includes the following cancers:

  • Oesophageal (adenocarcinoma)
  • Breast (postmenopausal)
  • Liver
  • Gallbladder
  • Kidney
  • Bowel
  • Multiple myeloma (a blood cancer)
  • Meningioma (a type of brain cancer)
  • Thyroid
  • Gastric cardia (part of the stomach)
  • Pancreatic
  • Ovarian
  • Endometrium (lining of the uterus/womb)
Links between overweight and cancer
The World Cancer Research Fund has analysed global research relating to body fatness and the risk of developing cancer. They have found the following links:

There is convincing evidence that overweight and obesity increases the risk of:

  • Oesophageal cancer (adenocarcinoma)
  • Pancreatic cancer
  • Liver cancer
  • Bowel cancer
  • Breast cancer (postmenopausal)
  • Endometrial cancer (lining of the womb or uterus)
  • Kidney cancer

There is probable evidence that overweight and obesity increases the risk of:

  • Mouth, pharynx (throat) and larynx cancer
  • Stomach (cardia) cancer
  • Gallbladder cancer
  • Ovarian cancer
  • Prostate (advanced) cancer

Research has also found a probable link between overweight and obesity and a reduced risk of premenopausal breast cancer. Similarly, body fatness in young adulthood has been associated with a probable reduced risk of pre and postmenopausal breast cancer.

Cancer Council WA does not recommend carrying extra body weight to confer a potential small decrease in premenopausal breast cancer risk as:

  • Being overweight significantly increases the risk of breast cancer after menopause - these postmenopausal cancers are much more common in the population.
  • It's difficult it is to lose weight, so it's unlikely that people would be overweight when they're young, and become lean at menopause.
  • Being overweight increases the risk of type 2 diabetes, heart disease, fatty liver disease and many other cancers.
To find out more about how overweight and obesity can increase your cancer risk see the position statement on overweight, obesity and cancer prevention.