Despite leading the industrialized world in obesity, America is obsessed with being thin. Fashion magazines are filled with unrealistic - and for many, unattainable - images of the perfect body, fueling a billion-dollar industry of exercise fads, diet books and nutritional supplements. The Kindest Cut:Debbie Mackenzie was desperate to lose weight. So she decided to take a radical step: she got gastric bypass surgery. Did it work? Find out. Beauties' Ugly Secret: Famous for their pinup calendars, the Barbi Twins made a handsome living displaying their bodies. But they were hiding a dangerous diet secret. Now they reveal it. Weight Of The World: Owen McKibbin, one of the top male models in the country, has been featured on countless covers of men's magazines. To maintain his physique, he follows a grueling regimen of diet and exercise. But increasingly large numbers of men are taking dangerous shortcuts, and are suffering from severe eating disorders. At Your Own Risk: Margo Ellis lost 107 pounds; she says she owes it all to an herbal diet supplement. But Doug Hanson believes that same supplement is partly responsible for his wife's death. Is ephedra safe?