One of the last socially acceptable prejudices is that against the obese. Fed by a steady stream of diet books, TV shows, and even documentaries, the stereotypes are constantly reinforced; overweight people are heavy simply because they eat too many Big Macs and french fries; they're desperately lonely and gorge themselves out of despair; they're couch potatoes who just refuse to exercise. These are, of course, caricatures of a complex problem that affects millions of people.

As Rockefeller University molecular geneticist and obesity researcher Jeffrey Friedman argues in "Wired to Eat," obesity is a disorder that is largely caused by genetic factors. For more than a decade, Friedman has visited the remote Micronesian island of Kosrae in an attempt to pinpoint the specific genetic and molecular reasons why the population, descended from a mix of Micronesian and European ancestors, exhibits such a high rate of obesity. He and his colleagues at Rockefeller collected medical information on the entire adult population of some 2,500 islanders and now have begun detailed analysis of the DNA to identify specific genetic variations that are associated with obesity. If Friedman succeeds in finding genetic causes for the island's obesity and health problem, it will have immense implications for how we view overweight people. "We have to realize that obesity is a disease, like cancer, that people have less control over than most of us think," maintains Friedman.