I have 2 fire-belly toads and a young green frog. They eat as much as they can cram into their little mouths. The frog seems to be getting fat. So I am wondering how often should I feed them, how much at a time, and are overweight frogs/toads a problem? Thanks for any info.

Frogs can get fat but I've not heard of it being a gross (pun intended) problem. How much and how often they need to eat depends on their sizes, ages, temperature, etc. You might feed them once a day as much as they eat in say 10 minutes or twice a day in smaller amounts. Most reptiles and amphibians can go a while (days for some, much longer for others) between meals, especially if those meals are proportionately large compared to their size. The more eager they are to eat, the more they need to be fed. Once satiated, their interest in the food should wane. What are you feeding them?

I feed them mostly crickets, but also 'found' bugs like daddy-long-legs which I find in my home. By the way, in today's news there's another mention of the worldwide decline of amphibians. They're not doing so good these days, which is one reason why I am 'friend of frogs'. They seem to need all the friends they can get.

An adult green frog might eat three large (or three times that many small) crickets every day or so would be my guess. A firebelly toad might eat a few large or more small ones. Since your green frog is young, he probably eats less. How much they eat depends on the temperature as well.