Celery, lettuce, cucumber, tomato and carrot are some foods that are very low in calories. Vegetables and fruits tend to be among the lowest calorie foods because they are high in water and fiber and low in fats, proteins and carbohydrates.
Some very low calorie fruits are peaches, grapefruit, strawberries, watermelon and papaya. Depending on the size, one peach contains about 37 calories. Half of a grapefruit also contains about 37 calories. One cup of watermelon or sliced strawberries contains around 50 calories.
Some packaged foods are also low in calories. Look for packaged foods that are sugar and fat free, such as sugar-free Jell-O. Sugar-free Jell-O in any flavor contains about 10 calories per 1/2 cup serving. Other packaged foods that are low in calories include no-sugar-added Dryer's Whole Fruit Bars and Dole Fruit Juice Bars. These frozen desserts each contain about 30 calories per bar.
Vegetables that are naturally low in calories include Brussels sprouts, broccoli, cabbage, beets and cauliflower. All these foods are low in calories by themselves, but certain methods of preparation may significantly raise the calorie count of a dish. For the lowest calorie count, eat fruits and vegetables raw or with a low-calorie dip.