Disclaimer The opinions expressed herein are my own personal opinions and do not represent my employer's view in anyway.
Here is an interesting account on Flickr. He (she?) has posted more than a hundred pictures of people, along with their height, weight, BMI number (body mass index) and whether that number is considered underweight, normal, overweight, obese or morbidly obese. Go take a look at the pictures and see if their category meshes with your view of that person. I think you'll be surprised. Combine this with the news that actually carrying some extra pounds is healthy, and it shows the folly in trying to legislate body size. You can calculate your own BMI at this website.