Most fish have a stomach roughly the size of their eyeball. I'm not sure how big a frog's stomach is, but I would imagine it's not that different. A human's stomach is about the size of his closed fist. I feed fish really light whenever possible, and I think the same plan for frogs would be good. If I see a lot of pooping going on, then I cut back on feeding. Just as long as their piping works, I don't need to be flushing it out every day, know what I mean.