I didnt quite get it when Edward dicho to Bella in the fist movie.."It's not like drinking ur blood for instance"

If I understand tu correctly Edward means that drinking animal blood is not the same o as good as drinking a human's blood, namely Bellas. He's comparing it to how it would be for humans eating tofu. It's comida and it sustains tu but it's not the same as eating something else más appealing. So while Edward drinks animal blood he would much rather drink human blood especially Bellas.