The best thing to do is not have junk food in the house, if you can't stop with eating a single portion. Replace the chips, cookies, etc with fresh cut up veggies, such as carrots, celery, radishes, broccoli, or cauliflower. You'll get the same crunch, but you'll get nutrition instead of the fat and empty calories. If you need the salt, sprinkle on just a tad of sea salt to add a bit of flavor.