> If the are so attracted, naturally, to childbearing women, why do they want women to stay slim?

Maybe because when a woman is slim you are better able to feel / assess whether she is pregnant with (someone elses?) child?

> Why do they run in fear the moment anything of childbearing and parenting hits the discussion?

I didn't say anything about parenting. I was talking about reproduction ;-)

I'm wary of evolutionary 'just so' explanations. There are some good evolutionary explanations out there, but the majority of them are 'just so' stories, basically. I'm not terribly persuaded by the evolutionary account that I shared, but I thought it was interesting, at any rate.

Even if the above account explains some aspects, many things have evolved since then! People living in developed western nations have much lower instance of (especially childhood) mortality. The cost of living means that children are a considerable EXPENSE rather than a MONEY EARNER. While once our children's ability to gain resources was our retirement scheme, now we save for retirement ourselves. Where once being physically fit was ones ticket to obtaining resources (and the investment was sustaining the child into adulthood) now ones ticket to obtaining resources can consist in a (very expensive) ivy league education. People in developed western societies tend to have a small number of children but invest considerably more resources in those children for a much longer period of time in order for them to go on to be healthy productive prosperous members of society. Quality of lives rather than quantity of lives tends to be the thing. Kids tend to do better when they receive considerable time and emotional and energy imputs from their fathers. Kids tend to do better when they are raised in emotionally loving environments. Raising kids (rather than dragging them up) gets us well beyond evolutionary considerations around leaving the greatest possible number of kids. Hell, we PAY sperm donors these days, they don't pay for the privaledge of donating!!!