Boredom!!

I do the same thing. When this happens, particularly if you're not really doing much like watching TV, find something to do with your hands to keep you from going to the kitchen. Since I like arts and crafts, I'm learning how to make chainmail stuff. Now I realize that chainmail is a little "out there" for some people, but it's the idea that counts. My aunt crochets to keep herself from snacking. Try finding something you like (or learning something new!) to keep you busy in your bored times. I hope that helps!