Being overweight or obese was found to be linked to an increased risks of 10 types of the most common cancers.
The researchers estimated overweight or obese individuals could contribute to 12,000 extra cancer cases in the U.K. every year, the BBC reported. The findings were published in the journal the Lancet.
"Although the relationship between cancer and obesity is complex, it is clear carrying excess weight increases your risk of developing cancer," Tom Stansfeld, at Cancer Research U.K. told the BBC. "Keeping a healthy weight reduces cancer risk and the best way to do this is through eating a healthy, balanced diet and exercising regularly."
The five-million participant study is the largest to date, and revealed if the obesity problem continues to rise there could be an additional 3,700 cancer cases diagnosed every year. London School of Hygiene and Tropical Medicine researchers monitored the health changes on the study subjects over the course of seven years. The team found for every excess 13 to 16 kilograms of weight there was an increased risk of developing six types of cancers.
Being overweight imposed the highest risk increase for cancer of the uterus. It was also found to have an effect on cancers of the "gallbladder, kidney, cervix, thyroid" as well as leukemia which had the lowest risk, the BBC reported. People with a high body mass index were also more likely to develop cancers of the "liver, colon, ovaries, and post-menopausal breast cancer," although the precise effects on these cancers was not as clear.
"Risk of cancer of the uterus increased substantially at higher body mass index, for other cancer we saw a more modest increase in risk or no effect at all," Doctor Krishnan Bhaskaran, who led the research, told the BBC. "This variation tells us BMI must affect cancer risk through a number of different processes, depending on cancer type."
