Women who have a higher waist to hip ratio could have an increased risk of womb cancer, a study suggests.
Researchers writing in the British Medical Journal (BMJ) found that for every 0.1 unit increase in the ratio between waist and hip, the risk of developing the disease increased by 21%.
Experts from the World Cancer Research Fund (WCRF), which part-funded the study, said the results showed a strong relationship between cancer and carrying extra weight around the waist.
Women can work out their waist to hip ratio by dividing their waist circumference by their hip measurement.
A woman with a ratio of 0.7 which then increased to 0.8 would have a 21% greater risk of developing womb cancer, the study suggests. An extra 0.1 increase would raise that risk even further.
A ratio above 0.85 for women or 0.90 for men is a sign of obesity.
The WCRF estimates that about 25,000 cancer cases could be prevented every year in the UK if people were a healthy weight.
Professor Konstantinos Tsilidis, from Imperial College London, said: "These results demonstrate how important it is for women to make sure they maintain a healthy weight in order to reduce their cancer risk."
Dr Panagiota Mitrou, director of research funding at the WCRF, said: "We know that extra weight around the waist increases the risk of a range of health conditions, such as diabetes, but this important study is helping us shine a light on how body fat around the waist could affect cancer risk.
"It is incredibly important that people are aware of the dangers of excess body fat, particularly around their waist. After not smoking, maintaining a healthy weight is the best thing people can do to help prevent cancer."
The study also found associations between waist to hip ratio and bowel and pancreatic cancer, although these were not as strong.