Obesity, skiny, tall, short, unibrow, hairy, flat figure

[A-Man]

I could agree with everything you've said, except here:

but its not unfair to use a statistical trend as a frame of reference for a group of people.

"No amount of experimentation can ever prove me right; a single experiment can prove me wrong." -Albert Einstein.

It's straight up wrong to generalize as long as there is a single exception; 5% means 1 in every 20 overweight people you meet everyday do suffer a genetic problem associated with it. None of those who were arguing mentioned anything about these few exceptional cases, but sticked to what was more like "Obese people have no excuse, and therefore they're all fat cuz lazy". I am not promoting genes as an excuse; all I am try to do is clarify that it's not fair to jump to conclusions every time they encounter a fat person.  

People who work to lose weight usually do so not from "I don't want to be ostracized", but from "I want a better body for myself and look better".

Not right. Have you ever wondered why bullies are stereotyped as fat boys? It's nothing but a result of those trying to manifest themselves in the community in the way they found to be best; to be a "bad boy".