Is he just a bit "chubby" or are you being PC and he's actually more along the lines of obese?

On the one hand, maybe you could give him a chance if he's just a little overweight. Maybe things will be pure magic and the little extra weight won't even bother you anymore.

On the other hand, if you're just not feeling it...maybe its best to not respond because you don't want to string him along.

On another hand (wait, too many hands here, but you KWIM!), its JUST one date! Nothing more, nothing less, just you going out and having a good time with someone. And given the fact that MOST people who meet online don't end up "clicking".....I say just go for it because what do you have to lose? One date doesn't mean much of anything, especially not a commitment! You're both still feeling each other out at this point.

Take a leap of faith and meet the guy!