If you were only looking for a comparison you wouldn't have used yourself. You're hoping that you can somehow gain a few sympathy points by letting people know you're a fatty. You also hope that your thread will put weight (No pun intended) on smokers and coffee drinkers, and by extension making overweight slightly more acceptable.
Get on a treadmill and start a diet, then you're allowed to argue the health issues of others.
p.s. He didn't need to "try to get into" your head, the way you talk and behave pretty much opens a gateway into your skull. You can try to nervously laugh it off if you like, but I'm afraid it does you little good.