Why our research matters

Considerable evidence suggests that obesity and overweight play an important role in cancer. Obesity and overweight have been clearly associated with increased risks for kidney cancer in both men and women (two-fold increased relative risk), and in women, endometrial cancer (one and a half-fold relative risk) and postmenopausal breast cancer (two-fold relative risk). Building evidence suggests that obesity and overweight also are associated with an increase risk of colorectal cancer, gall bladder cancer, and perhaps more modestly, the risk of thyroid cancer in women. For colorectal cancer, the effect of obesity and overweight on risk may be due in part to low physical activity, as consistent evidence exists for a strong protective effect of physical activity against developing colorectal cancer. Recent studies suggest that obesity and overweight may also play a role in the increasing incidence of some types of esophageal cancer, possibly through obesity’s association with gastric reflux. For prostate cancer risk, inconsistent findings from studies evaluating obesity may result from limitations in the measurement of obesity, as more consistent results have come from recent studies of biological factors that are more directly associated with specific aspects of body composition (e.g., total fat). For other types of cancer, in general, too few studies have been conducted to draw conclusions about the relationship between obesity and risk of disease development. However, strong experimental research in animal models of cancer development and disease progression have shown that maintenance of adequate and not overweight body size can delay development of cancer. Whether this can be achieved in humans has not been evaluated in prospective randomized trials. (Center for Disease Control)

U.S. Obesity Trends – Center for Disease Control