When my frogs were juveniles I'd offer them food every night, they'd usually eat 4-6 1/4" crickets or a chunk of nightcrawler. Sometimes they'd choose not to eat at all. Once they get to around 2-3 months or so they'll stop wanting it every night and then you can feed them about 3 times a week. So far with my frogs, they know when they're full. I haven't had any problems with them over eating even when offering every night.