Snickers is lovely. Such a cutie! We have guinea pigs and I just think that some are fatter than others. The pet store I got my last one at (on Saturday) said something I had never heard which was to feed them unlimited hay and carrots and only a single bowl of the pellets a day. I've never limited food in any way, but they said that the pellets are what makes them too fat. *shrug* I don't really know, I had just never heard that before.
ETA: So sorry for your loss of your hamster.