There's some research to suggest that the scent of a baby's head triggers the release of dopamine in some women, which is associated with feelings of pleasure. (romper.com)
As a person gains greater tolerance to sugar, more is needed to elicit the same feeling of pleasure. (onnit.com)
But food is wired very strongly in most brains to produce a powerful feeling of pleasure so that we survive by continuing to feed ourselves. (psychologyofeating.com)