Scientists at the University of Bristol, England, have concluded that overweight and obesity increase the risk of cancer by at least 2 times, MedicalXpress reported.

Experts have identified what is the genes’ activity in malignant tumor tissue in 8 cancers that have been linked to obesity, BTA reported.

They then resorted to the Mendelian randomization method, which is related to the study of natural alterations of genes. The method is using measured variation in genes of known function to examine the causal effect of a modifiable exposure on disease in observational studies.

In this case, a link between the body mass index and the risk of disease was found, excluding the influence of genes that could contribute to both obesity and the onset of tumors.

According to scientists, overweight is responsible for 6 percent of cancer cases in developed countries. The study also found that obesity-related cancer rates are much higher.