ABSTRACT
Over the past couple of decades, substantial evidence has mounted to support the role of obesity in the development and survival of people with several types of cancer. In 2016, the International Agency for Research on Cancer concluded that there was sufficient evidence that excess body fatness, or obesity, was a cause of 13 types of cancer including the colon and rectum, esophagus, kidney, pancreas, stomach (cardia), liver, gallbladder, meningioma, thyroid, multiple myeloma, and additionally endometrium, breast (postmenopausal only), and ovary in women. Abdominal adiposity has also been associated with a higher risk of several cancer types, particularly gastrointestinal tract cancers such as colon cancer. Weight gain during adulthood has also been associated with some female reproductive cancers. However, research on the potential impact of weight loss is limited, but emerging evidence suggests that even modest weight loss is associated with lower breast cancer risk. Associations have also been documented between obesity after diagnosis and higher mortality for breast, colorectal, and endometrial cancers. Additional links between obesity and cancer continue to be uncovered, but it was estimated that between 2011 and 2015 4.7% of cancers in men and 9.6% of cancers in women were attributed to excess body fatness.
