All this week, Minnesota Public Radio is looking at the growing rates of obesity in the state. Doctors and public health advocates worry Minnesotans are gaining more and more weight. The situation also presents a fundamental and frightening challenge for health insurance companies. Some say the industry is not adapting fast enough. HMOs say Minnesotans themselves need to start living healthier lives. Mainstreet Radio's Jeff Horwich has the latest in our series, "The Fight Against Fat."