They're blunt, but honestly a big part of it come down to communication and finances. Once someone gets too fat they start having difficulties signing because their arms get hard to lift and it gets hard to make the right handshapes. Also, most of the Deaf community here is just broke. Most of the community didn't buy anything to drink because they couldn't afford it. They aren't going to get particularly large given the amount of food they can actually afford to buy. As for the others I don't know a huge amount about them. It also might be because they mainly bike/walk rather than drive, which saves money and fights obesity.