If you could go for a walk after dinner, it might be a big help. You don't have to be real athletic if you don't feel like it - just a nice walk. It seems to reorient the mind.
When I quit smoking sometimes I would just have to take a shower to get my mind off cigarets because that was the only place I never smoked. Some days I was real clean!
Also, if you aren't eating enough during the day your body may be telling you to feed it.