Not only are you hungrier when you're tired, you're less likely to make positive food choices. A recent study found that sleep deprived adolescents were more likely to choose high calorie/low nutrient foods than healthier alternatives.
If you've noticed the insomnia pounds piling on, skip the drive-thru and hit the stationary store. Keeping a journal to track eating and exercise habits has been shown to promote weight loss and healthy-weight maintenance.