As Lian said, not all snakes will eat whilst the shedding process has started.
At this time they don't necessarily like being handled as much either. Their skin irrates them, and they are nearly blind so get scared easily.
Saying that my snake still eats whilst shedding, and will happily slither onto my hand and be picked up.
Ensure you keep the fresh water in the vivarium, and if you can raise the humidity slightly. You can do this by adding another water dish on the warm side, or by sparying water inside every now and again. This is by no means essential, but will help your snake's skin come off easily.
As soon as he has shed, you can handle and feed him as normal. It's also a good idea to check the shed skin to make sure all of it has been removed (including the eyelids and tip of the tail).
Hope this helps