My guys LOVE BB, but there are only certain flavours that they will eat (go figure) . Usually the turkey is a hit, but anything other than that is a little more hit and miss. But you are right, they will eat a lot less on BB than other types of food.

Think of it this way, when you eat lots of rice (i.e. filler) when you have Chinese food, you are hungry again in a few hours. Cats are like that with some brands of dry cat food because there is lots of corn (i.e. filler) and when we free feed them, they just go back again when they are hungry...