Hamsters can eat bread, but it is preferable to give hamsters healthier snacks of fresh vegetables and fruits for optimal nutrition, reports the ASPCA. Hamsters cannot be given rhubarb, grapes or onions because these are toxic to hamsters.
Hamsters are also highly sensitive to changes in food so any time that a new food is given, it should be introduced slowly. These animals should also always have access to clean water in their cages. The main diet for the hamster should consist of commercial seeds and commercial pellets. Although hamsters eat insects, it is not necessary for pet owners to provide them with insects to eat.