Breast milk not fatty enough??

Breast milk not fatty enough??

My DD has been acting like she's starving. 24/7. I don't mind her always being on my boobs..but even when she's eating she's crying and freaking out because she's hungry. I asked pediatrician about it and she told me my breast milk probably isn't fatty enough and I'd need to supplement with formula some.. So I gave my DD 2oz of formula after she had been eating for over an hr. Filled her up but I don't want to supplement. Is there a way to make my milk more fatty?