Just keep a constant supply of food in a bowl in his home. That's what I used to do. Don't worry too much if you forget to feed him once. Hamsters are hoarders. They always take a lot of food and hide it their "nest". When you clean his cage, you can see where all the hidden food is.

If you are really worried, just feed him. Hamsters don't usually overeat. They'll just save the extra for later.

((((Hamsters))))))