Unfortunately this is an innate behavior that some dogs have and most likely will always have. The male is trying to insert his dominance in their little pack. It may become better once your female realizes and accepts his dominance but you cannot rely on that happening, as you can never if or when it will actually happen that way. Its better to fix it before one or both dogs, or even you, gets hurt. We went through the same thing when we rescued our 2nd female. She was a stray and was very food aggressive. She attacked our 1st female on more than one occasion over food. Some tips that helped us: we never give them food out of the same bowl (it took us many months to feel comfortable given them water out of the same bowl), we feed them on separate sides of the room (in an extreme case, I suggest even feeding them in completely separate rooms), in the beginning we would always be in the room with them while they were eating, and we consulted a trainer about it. We also began feeding our 1st female, the less dominant one, first to show patience to our 2nd one, to upset the dominance roles and to show that I ultimately decide who gets fed first and when you get fed. Who eats first is a big role and dominance influencer in doggie world. BUT…I am not a professional and even though we all love our pits we got to remember that they are pit bulls, a very strong breed that is not to be taken lightly. I strongly suggest that you talk to or meet with a trainer, especially where it seems this aggressive behavior is relatively new. They may be able to give you better guidance and tips on controlling the situation or even reversing your male’s aggressive behavior. But in the meantime, I hope my tips help you out. They did do wonders for us, although our 2nd female is still aggressive with some food and treats.