Celery: A staple on most party veggie trays, celery (without the ranch dressing) is a crispy snack that you can enjoy without worrying about taking in any calories. It is high in sugar and sodium, but still much healthier than pigging out on brownies or salty peanuts.
Oranges: Before you leave for work in the morning, toss an orange into your bag for a mid-morning or late afternoon snack. An orange typically contains only 45 calories, so feel free to eat the whole thing!
Strawberries: Strawberries are a popular negative calorie food because of their natural sweetness and juiciness. Sprinkle a few on your breakfast cereal to give your metabolism an extra jumpstart early in the day.
Tangerines: A smaller, more tart version of the orange, tangerines are another negative calorie food that's both tasty and portable. Enjoy one or two for a snack throughout the day to stimulate your taste buds without having to dig through the candy drawer.