Could my russain dwarf be a hybrid? or is he just fat 😕

[HammieMumma]

Hi,

This is my first post on here but I have actively used this website daily since I got my hamsters.

Basically I'm not sure if my russian dwarf could be a hybrid as he weighs a lot more than the typical dwarf hamster. He doesn't look too fat tbh but he is rather lazy and refuses to excercise!!! I have tried putting him on a diet but he just got heavier! I'm worried about him and feel like a bad hammie mummy as I don't want him to have any health issues because I can't refuse him a treat. I will attach a photo below of him to see what you all think?

Thank you.

Hammiemumma to Tommy the Russian dwarf and Quinn the syrian