Counting calories is an essential component of most diet plans. Guessing the amount of calories in a given food is often difficult, causing dieters to eat too much or go hungry from eating too little. The following list of calorie values in common foods can take the guesswork out of monitoring your diet.FruitsMost fruits are low in calories and are a great source of nutrients and energy. A medium-sized apple contains 80 calories, one medium orange has 71 calories and one nectarine contains 88 calories. Bananas have an average of 160 calories, one cup of cantaloupe contains 48 calories and one cup of pineapple contains 80 calories. A cup of strawberries has 53 calories, one prune contains 20 calories and one cup of watermelon has just 45 calories.VegetablesVegetables are lower in calories than most fruits and are packed with essential vitamins and minerals. One serving of celery contains just nine calories, one cup of iceberg lettuce has seven calories and ten medium radishes contain about eight calories. One cup of onions contains 65 calories, the same amount of green beans contains 31 calories and one cucumber contains around 30 calories. One cup of fresh carrots contains 30 calories, one cup of asparagus contains 36 calories and one medium sized tomato contains 26 calories.Dairy ProductsDairy products can be high in calories but provide calcium, protein and other vital nutrients. One ounce of feta cheese contains 75 calories, an ounce of mozzarella contains 80 calories and the same amount of swiss cheese contains 107 calories.1% milk contains 104 calories per cup, while 2% contains 121 calories. Buttermilk has an average of 99 calories per cup and skim milk remains the most healthy option with 86 calories per cup.MeatsMeats are an important source of protein but may be high in calories. Four ounces of beef can contain between 220 and 350 calories depending on the cut of meat. One serving of venison contains 143 calories, a serving of ham contains 201 calories and one serving of **** contains an average of 268 calories.