The working group of the International Agency for Research on Cancer (IARC) published a report in the New England Journal of Medicine pooled over 1000 epidemiological studies on the impact of excess body weight on the incidence of cancer.

On the basis of the available data, the researchers concluded that the absence of excess body fatness lowers the risk of most cancers. In addition, a review of studies in experimental animals and mechanistic data suggest a causal cancer-preventive effect of intentional weight loss, although evidence in humans remains to be established.

In 2013, an estimated 4.5 million deaths worldwide were caused by overweight and obesity; on the basis of recent estimates, the obesity-related cancer burden represents up to 9% of the cancer burden among women in North America, Europe, and the Middle East.