There are too many reasons that people gain weight, sickness, genetics, medications, lack of mobility, , etc. The body's metabolism actually slows down as we age, thus we have to cut the amount of calories we eat each day to keep from getting fat. Increasing your activity is not usually the answer as we age. That's why we get the "middle age spread".
I have never seen anyone Dfd for obesity and there are a lot of obese jws. I have also never seen anyone Dfd for physical uncleanness , but there are some I avoided sitting next to or riding in a car group with, if posible, due to the outright stench.
What is interesting is that obesity is about to overtake cigarette smoking as the number one cause of premature death. That line the jws use to keep our bodies undefiled by not smoking could just as easily be used for morbid obesity. Both are great health risks.
Not that I think the jws should Df for obesity, but rather this totally blows their argument to Df for smoking. Basically, they just need to try and look at the heart, as one poster mentioned, and encourage people. While they are at it, they need to stop Df people period.