Almost half of cases of womb cancer in the UK - about 3,700 a year - could be prevented through keeping slim and active, a review of data shows.
Researchers at Imperial College, London, say women can reduce their risk with at least 30 minutes of daily exercise and keeping a healthy weight.
The World Cancer Research Fund report also found that coffee may reduce risk.
But experts say there is not yet enough evidence to recommend drinking coffee to protect against the disease.
Womb cancer is mostly diagnosed in women aged over 60
Symptoms include abnormal vaginal bleeding or discharge and, less commonly, pain in the lower abdomen or during sex.
There is no reliable screening system to detect womb cancer among the general population
Endometrial cancer - cancer of the womb lining - is the fourth most common of all cancers in women in the UK.
In the first global analysis since 2007, Imperial College London researchers collated and reviewed scientific research on endometrial cancer, and links with diet, physical activity and body weight.
The study found evidence that about 3,700 cases could be prevented every year if women were active for 38 minutes a day and maintained a healthy body weight.
In the UK only 56% of women follow recommendations to be physically active for at least 30 minutes a day, five days a week, while only 39% have a healthy weight.
Study author Dr Teresa Norat of Imperial College told the BBC: "If you are physically active and if you don't have excess body weight you can reduce your risk of womb cancer and improve your health in general."
Karen Sadler, executive director of the World Cancer Research Fund added: "The evidence on coffee is very interesting and is a further indication of the potential link between coffee and the risk of cancer but a lot more work still needs to be done.