Hamsters are Omnivores so I really like to feed them a considerable amount of Vegetables and Animal Protein (mealworms, chicken etc.) during the day. I use Harry Hamster Tiny Friends Farm Mix which is basically nuts, seeds and vegetables. Personally, I would kind of avoid treats with
a lot of sugar in them because I get weary about diabetes, even though they are more likely to trend in Dwarf Hamsters it still puts me off. Treats should obviously not be given every single day but now and then is completely fine!
)
-Hope this helps