Obesity has been well-proved to increase the risk of developing diseases such as type 2 diabetes, heart diseases, high blood pressure, gall stones and osteoarthritis but its link to cancer and death related to cancer is less known.
To find this a study was started in the U.S.A in 1982 on 900,000 adults (404,576 men and 495,477 women). All the participants were free from cancer at the beginning of the study. After a follow-up of 16 years it was observed that the heavier people (with BMI at least 40) in the study group were more at risk of developing all types of cancers. The death rate of heavier people due to all cancers combined was 52% more for men and 62% more for women as compared to the rates in men and women with normal weight.
The cancers found to be strongly linked to obesity were those of the liver, kidney, pancreas, esophagus, colon and rectum, gall bladder and breast. It was also estimated that about 1 in 6 men and 1 in 5 women are at increased risk of dying from cancer due to excess weight. In this study obesity was found to be significantly associated with higher rates of death due to cancer of esophagus, stomach, colon and rectum, liver, gallbladder, pancreas, kidney, prostate in men and breast, uterus, cervix, and ovary in women.