I can't believe that I am responding to this, but here goes.
If it were the food theory like you said, then women would love boobs as well.
There has been a theory related to this. It is evolutionary in nature. I forgot who espoused it, but an old drummer told this to me. No drummer jokes here please, he's was a scientist for NASA.
Long ago, female humans like other mammals only had enlarged breasts while they were in gestation. When they weren't pregnant, their breasts would shrink back to a size similar to males. Enlarged breasts were a symbol to her male mate that she was pregnant and needed protection. So, as long as she had enlarged breasts her male mate would stay with her, and once she wasn't he'd leave in search of new fertile grounds. In the eveoltionary scheme of things, the women who maintained the larger breasts after gestation were most likely to survive because of male protection. So in the survival of the fittest, the girls with big breasts won out.
I am not espousing the truth of this theory, nor do I necessarily subscribe to it. But this a theory that was mentioned to me, and I'm just throwing it out there.
