I haven't read the book, but from the excellent synopsis (thanks Meg), it sounds very interesting. As far as society's views, I think we shouldn't simply view obesity in isolation, but should consider all the symptoms that stem from the various forms of disordered eating (from compulsive over eating to anorexia, and the whole range).
Telling an obese individual to "eat less and move more" is akin to telling an anorexic to "just eat a sandwich." It's also probably similar to someone addressing a person battling depression and telling her to just "snap out of it." When it comes to mental disorders, empathy can be very difficult. I feel that obesity is generally treated as a physical condition (hence the eat less, move more "solution") and so we never get to the root of the problem.
I wouldn't consider prejudice against obese people to be the last socially acceptable form. There's prejudice against anyone who doesn't fit into that magical range of what it means to be "normal."
"Act as if it were impossible to fail." - Dorothea Brande