Medium rat too big?

[mainbutter]

So since hes been on sm rats could that be why hes not really gaining weight?

Ove only had him 3 weeks.and ive just been feedong what his previous owners were.
But i think hes big enough to go to mediums.

A nearly 1000 gram male not noticeably gaining weight over 3 weeks.. not a surprise for me.

He's big enough to handle mediums, but I prefer my males to stay on small rats in general. Trim snakes are active breeders!

I start feeding mediums to females in the 700-800 gram range usually.