More than a fifth of women in Northern Ireland are obese - and are 40% more likely to develop cancer, it has been claimed.
Cancer Research UK said that 22% of women here are obese, slightly lower than the UK average of 25%.
The cancer charity warned that obesity raises a woman's risk of developing at least seven types of cancer - including bowel, post-menopausal, breast, gall bladder, womb, kidney, pancreatic and oesphageal.
In the UK it is estimated that 18,000 women develop cancer as a result of being overweight or obese each year.
Every year in Northern Ireland around 540 women are diagnosed with bowel cancer, 1,300 with breast cancer, 30 with gall bladder cancer, 230 with womb cancer, 85 with kidney cancer, 110 with pancreatic cancer and 60 with oesophageal cancer.
Newry woman Caroline O'Hare had been obese after having her family, but lost an incredible ten and a half stone over the last year after joining Weightwatchers.
She said she was motivated to lose weight to ensure she had the energy to care for her children, and to make sure she would be around for them.
"I was aware of the risks associated with the extra weight - heart disease and some cancers," she said.
"I wanted to be fit to do things with my family, thank god I never experienced ill health, but it was something that had always been a worry."
Cancer Research UK spokeswoman Jean Walsh urged women to make small changes to lose weight if they are obese.
"Losing weight isn't easy, but women don't have to join a gym and run miles every day or give up their favourite food forever," she said.
Cancer Research UK is holding Race for Life across the UK to encourage women to become more active.
"Race for Life events are non-competitive," Jean said. "Taking part is not about being fit or fast and participants can choose to walk, jog, or run around the course. The atmosphere is incredibly supportive and pledging to take part, alongside thousands of like-minded women, is a great motivation to get fitter as well as raise money for life-saving research."
Race for Life Pretty Muddy, a 5K mud-splattered obstacle course, comes to Northern Ireland for the first time this spring. Entries are open for the event on Saturday, May 30, at Ormeau Park, Ormeau Road, and on Sunday, May 31 there is a 5K and 10K Race for Life at Stormont Estate, Belfast.
To enter Cancer Research UK's Race for Life Pretty Muddy, visit raceforlife.org or call 0300 123 0770.