I don't think that when people say "fed is best" they mean "there is no difference between formula and breast milk".

They mean "a mother will try to do what is best for their baby, and sometimes breastfeeding in this particular situation is not best as it will lead to malnourishment for the baby (if the mother can't breastfeed or has mastitis or something like my mother did), so whatever gives the baby the most nourishment available to them at the time is best for THAT PARTICULAR baby at THAT PARTICULAR time".

Also, the argument that "mortality and morbidity rates are higher for infants who are fed anything but human milk" doesn't necessarily prove causation between formula and mortality/obesity. It could also be demographic correlation.

My mother physically could not breastfeed. She tried her best but her milk ducts were blocked and she got extremely bad mastitis and wasn't able to produce enough milk to feed me (let alone my brothers).

She was told that if she formula fed, her kids would be intellectually stunted and malnourished and never reach their full potential so she was wracked with guilt over a choice she HAD to make or I would starve.

18 years later I graduated school in the top 1% of the state... I guess I would have been Einstein if I had been breastfed, who knows? LOL

My brothers are all 6 feet tall or higher, and I'm 5'10" so I guess I wasn't malnourished. Oh and none of us are obese.