I'm going to decline a second date as the guy was more out of shape than I realized.
What makes this a reason for turning down a second date?
His waist is bigger than mine and that's not what I'm into.
It is shallow to put too much importance on someone's body. This may be a really nice guy.
I don't care. I want my physical needs met. If he's not in shape, I'm not interested.
Judging someone solely on their body type is shallow and you might be passing up on a future with a really wonderful person. We all are attracted to different people so if you do turn down the second date, just make sure to do so with respect for his feelings.