I am also nursing my newborn and today looked up what to eat/not eat. Its pretty much the same as when preg. Watch the caffeine intake because its passes in milk. Watch the citrus too because it can upset babies tummy and effect thier poop. The rest looked about the same as fir fish, drugs, alcohol. ...
Oatmeal is good for u and it doubled my supple of milk!
Just be sure to eat a balanced diet with plenty of vitamins. Continue to take prenatal vitamins and drink plenty of fluids. I never altered my diet while breastfeeding but did make sure I took in enough vitamins and fluids to produce a lot of healthy breast milk.