I've tried, but couldn't seem to find the right value, because it depends on the mood of your creatures. Take example, excluding the un-maxed creatures, if you have 40 maxed creatures, as long as you keep them at their highest bar (100 pts), you can't exceed 4000 pts (40 x 100pts) per week. Those points will decrease if you don't feed your creatures for the next 8hrs, maybe that's why it's hard to find the right value. Maybe someone else can figure it out, I’m not super familiar with how GG works.
It's different story for maxing a creature. You can just do that attributes' guide to level it up.