If you hate fat people, you love breastfeeding. The constant feedback loop between mom and baby's body teaches a baby to eat enough-but-not-too-much, only when truly hungry, and to crave the taste of the food his body needs to be healthy. (Mom can help this even more by eating a healthy and varied diet, as those flavors are passed along in her milk). Formula feeding teaches a baby that the correct response to any kind of distress is to suck down huge quantities of sugar, disregarding the terrible chemical flavors, and eat until they puke. Feeding formula when breast milk or donor milk is available is child abuse, and it should be available only with a doctor's prescription - and only dispensed in healthy amounts.  I'm not generally this much of an extremist on baby-care issues - but formula feeding really does tend to turn out little porkers with unhealthy guts.