An estimated 30.5% of American adults--nearly 59 million people--were obese in 2000, after their ranks had swelled 33% since the mid-1990s.1 But growing obesity rates are not confined to the United States, and the attendant health risks do not just include cardiovascular disease, diabetes, asthma, and arthritis. Cancers of the colon, breast, endometrium, kidney, and esophagus also are solidly associated with excess adiposity.2 (A link to prostate cancer is controversial.) In addition, obese patients with cancer have poorer prognoses. Caloric restriction offers some protection against the disease, but eating trends are clearly heading in the opposite direction.
Despite the situation's apparent urgency, only a handful of research-ers are examining the obesity- cancer link through experiments. Instead, the evidence is overwhelmingly epidemiological. The human data and some of the underlying mechanisms are "pretty clear," says Walter C. Willett, professor of epidemiology and nutrition at the Harvard School of Public Health. "It's ...
