Many men (I dare say MOST) are very good at blaming something external for the lack of desire because they are too insecure to say out loud the truth of it .... that MOST of them get bored having sex with the same woman no matter WHAT kind of shape the woman is in. I suspect this is the case. Just because he's (back) in great shape doesn't mean his libido is, and it is so much easier to point the finger of blame at the woman rather than do the hard work of looking at oneself to examine why he doesn't desire her as much any longer.

She may or may not be overweight. She may or may not be healthy. That's not the issue. He doesn't comment on whether or not HER desire has changed. HE is the one with the problem ... not her.