Thanks for your reply Cypher
I've found that my boys sometimes have a hard time eating the large red/green flat pellets in the Hazel Hamster mix. Maybe if I cut them into smaller pieces they might like them better.
I've decided to reduce the food amount as it seems that they don't eat all of their food. Whenever I had the boys together they ate most of the amount of food I fed them but now that they're separated (even though I cut down the amount of food they got) they don't go through food as fast.