Here are a few ideas...
1. Try doing something while you're watching TV, especially on the commercials. Learn how to knit or crochet! If your hands are busy, you won't be heading to the kitchen to get food!
2. Doing sit-ups, push-ups, jumping jacks, etc. on the commercial breaks is good, too.
3. Brush your teeth before you sit down to watch TV. For me, that makes food a lot less tempting.
4. Chew gum, drink lots of water, or drink hot tea.
5. Set a rule that you'll get your calories and nutrition in before a certain time of day, and don't eat after that time. It takes a lot of will power, but having a "rule" works for some people!