Do you find yourself nibbling on a bag of pretzels as you stare at a computer screen for hours? When you're sitting on your couch watching TV, do you get to the bottom of that popcorn bowl before the movie is halfway through? If you're bored, anxious, stressed, or even happy, you may reach for food without realizing it. If you're not careful, this kind of mindless eating can derail your diet and lead to weight gain. These 5 pointers will keep you from straying.