The food solution is simple, put it in a place where he just can not reach it! lol

As far as the digging, what some people do, is give the dog their own little sand box, you should fill it with dirt or potting soil as often regular sand is not thrilling enough to really "dig" in for dogs.

Get one of those sandboxes you would buy for a child, fill it with that stuff, and encourage your dog to dig in there. You can hide treats in his box to motovate him to want to dig THERE instead of anywhere else in your yard.

If you catch him digging in the wrong place, just say no, and guide him back to his sand box.