Can Hamsters Eat Bananas? Fat Hamster. Can Hamsters Eat Bananas? Residence » Hamsters » Can Hamsters Eat Bananas? The answer is sure, hamsters can eat bananas. Bananas are an excellent supply of dietary potassium and vitamin C, which are vital for hamsters. Hamsters are a preferred pet and many people want to know if they'll eat bananas. However, too much banana can cause weight gain in hamsters, so it is very important solely give them a small amount as a snack.