The point is, that you should not condone obesity, but at the same time, you should not condemn the obese. Obesity is a state, an object. The obese are people, that which is destined to overcome the negative. That said, if you uplift and make comfortable an obese person, it is harmful, if it is not followed by the positive reinforcement of behaviors that will lead to a healthy weight.

You: Hey!
Fatty: Hi!
You: Those clothes look great on you!
Fatty: Really?! Thanks!
You: Yeah! Come on, let's go!
Fatty: Where?
You: I wanna take you to see this thing on the other side of the park!
Fatty: The other side of the park? Way over there?
You: Yeah! Come on! Everyone will get to see how great you look in your outfit too!
Fatty: Well, I don't know...
You: It's going to be great! Let's go! You have to see this!
*Fatty gets some exercise, and enjoys doing it*