Feeding and growth rate

[Fin j]

Hi everyone. I am feeding my bullfrog about 50 crickets a week and some days i change and give him meal worms. Im not 100% on his age as the guy in the pet store said he was 4 to 5 months old but wasn't too sure. Ive had him for about two months and he's easily doubled in size and im worried that it could be from over feeding or is he having a growth spert
Any thoughts or advice will be greatly appreciated. Thanks guys