Several online resources exist to calculate the calorie content of fruits and vegetables. For example, caloriecount.com has an extensive list of fruits and vegetables and their respective calorie counts, in addition to other nutritional information about the foods.
The calorie content of some common average size fruits is as follows: apples are 44 calories; bananas are 107 calories. One hundred grams of blackberries are 25 calories, while grapes have 62 calories per 100 grams. A serving size of orange is 40 calories and one hundred grams of pineapple is 40 calories.
The calorie content of 100 grams of the following common vegetables is as follows: broccoli is 32 calories, while cauliflower is 30 calories. Cucumber is 20 calories and lettuce is 15 calories. Spinach is 8 calories, and onion is 18 calories.
Thinking about it in the opposite way, one can look at quantities of vegetables that equal 100 calories. Thirty-three spears of asparagus are 109 calories, one-third of an avocado is 107 calories, 29 baby carrots are 102 calories, three cups of kale is 109 calories, and 33 cherry tomatoes are 101 calories.
Vegetables that have been frozen or canned can retain their nutritional value if frozen or canned within hours of being picked. Once vegetables are picked, they steadily lose their nutritional value over time.