So how many calories is in an apple? a hard boiled egg? a package of instant flavored oatmeal? 2 mint Oreo cookies? It is easy to look on a package... if you have it near by, but what if you don't? and what is the serving size of what you are eating?
One web site I go to is http://www.calorieking.com/ You can look up your food item and it will give you a portion size and the calories, as well as nutritional content. As with any of the calorie info sites, sometimes the portions make no sense, so you have to be very aware and keep looking. All you have to do is google calories and the name of the item and there are many pocket size books with calories.
Now to answer those burning questions.... a large apple as 121 calories, a hard boiled egg has 13 calories, instant oatmeal, depends on the flavor.. 160-190 calories, and finally 2 mint oreos140 calories. Remember for your overall diet you need to look for nutrient dense foods, but if you are craving that Oreo, count the calories and don't punish yourself!