While I agree with your statement, I must first find out why a person is obese, is it from gluttony or a medical condition. I'm pretty sure gluttony is what you were referring to in which I agree.
As part of my message a few weeks back I talked about gluttony, a few comments came from the crowd that said, "Oh, boy...here we go". It's a sin in the Bible, I'll preach it just as hard as other sins.