We think food items always add calories to our body. But there few food items which actually burn more calories than they contain. These foods items burn more calories in their digestion than they contain. So replace your bag of potato chips with any of these for a healthy snack
A word of caution. As these food items have negative calories, if you limit your diet to only these items then it may lead to malnutrition. So eating them as just snacks but not as your full diet.