Being obese or overweight has become a growing cause of cancer, findings of a new study have revealed.

Preventable Causes Of Cancer

The study, which was published in the British Journal of Cancer, has found that excess weight is now responsible for 6.3 percent of all cancer cases in the United Kingdom. From 2011, the figure has increased by 5.5 percent.

Smoking remains a leading cause of the disease but the number of cancer cases linked to tobacco use is falling.

Based on 2015 cancer data, tobacco smoke is linked to about 32,000 cases of cancer in men, or 17.7 percent of all male cancer cases, and around 22,000 cases of cancer in women, which is equivalent to 12.4 percent of all female cancer cases.

Excess weight caused around 13,200, or 7.5 percent of cancer cases in women and about 9,600, or 5.2 percent in men. Overall, being overweight or obese caused 22,800 (6.3 percent) of cancer cases per year.

The third top preventable cause of cancer is overexposure to ultraviolet radiation through sunlight and sunbed, causing around 13,600 cases of melanoma skin cancer annually, or about 3.8 percent of all cancer cases.

Other preventable causes of cancer include eating too little fiber, which caused 11,700 cases of cancer, and drinking alcohol, which caused 11,900 cancer cases. Outdoor air pollution is also responsible for about 3,600 lung cancer cases per year.

The researchers said that the findings essentially showed that more than 135,000 cases could be prevented through lifestyle changes.

"Changing population-level exposure to modifiable risk factors is a key driver of changing cancer incidence," Katrina Brown, from Cancer Research UK, and colleagues wrote in their study, which was published on March 23.

"Understanding these changes is therefore vital when prioritising risk-reduction policies, in order to have the biggest impact on reducing cancer incidence."

Risks Of Excess Weight

Weight problems are often preventable through healthy diet and physical exercise. Unfortunately, many countries are facing an obesity epidemic.

People who are obese and have unhealthy eating and activity habits face a number of health issues. They are at increased risk for type 2 diabetes, gallstones, high blood pressures, heart disease, asthma and sleep apnea.

The findings of the new study provided evidence that excess weight is a significant risk factor for cancer. Being overweight has long been associated with higher odds for several types of cancer, including bowel cancer, breast cancer, and womb cancer.

"Obesity is a huge health threat right now, and it will only get worse if nothing is done," said Linda Bauld, from Cancer Research UK.