Distinction with ENORMOUS difference. Just admit when you're wrong.
It doesn't qualify as an ad hominem.
Oh and if you want to point out my typos, what is an ad honimem?
Please read again if you will, I pointed out your typo with an intended sense of humor, even noting that doing so could be considered ad hominem on my part. You seem to have taken that very personally, I meant to be humorous, and apologize if it was was offensive. Frankly, I make so many typos I almost never get a post out without editing it several times.
Also, I acknowledged, perhaps not clearly enough, that name calling is not always an ad hominem.
To answer your specific challenge, I will repost the Wikipedia definition of ad hominem I posted on post 19 above, apparently both you and BarnBoy missed it:
"Ad hominem (Latin for "to the man" or "to the person"[1]), short for argumentum ad hominem, is a logical fallacy in which an argument is rebutted by attacking the character, motive, or other attribute of the person making the argument, or persons associated with the argument, rather than attacking the substance of the argument itself."
Attacking the "character" could, in my opinion, including attacking their weight, although I understand it may not be as clear as "he is wrong because he is fat." But earlier in this thread someone made the argument that Bud Grant's fitness was a positive compared to a fat coach. I think you and I had the same opinion of that. Please also see post 26, where I tried to discuss the differences between ad hominem and name calling.
But respectfully, here is where I most materially disagree with you:
Calling someone fat, in my opinion, can have the effect of questioning their self control, and their worthiness of respect. In my opinion, this can be ad hominem without being as explicit as you require. In practice, saying "Fat Pat," or "Fatrick," can have the effect of saying "let me remind you that this guy is a fat person and we all know that fat people are disgusting and unworthy of our respect so why the hell would you care what he thinks?" If that is the intent of the name calling, it is an ad hominem. If not, it is not. I think quite often it is the intent. Again, that is my opinion. Since this cannot be definitively tested, we should probably respectfully agree to disagree. Also, I believe that name calling is no more constructive than ad hominem, so even if it just name calling, I do not like or respect it. That is what I meant about distinction with little difference. You may disagree with my perspective, but I don't think it is unreasonable.
Finally, "Just admit when you're wrong" is not a terribly compelling argument, and adds nothing to the conversation. Not sure if it is an argument from authority (yours in this case?) or proof by intimidation, but either way it is not terribly constructive.