One of the things we find on a well-formulated ketogenic diet is that the body’s hormonal response to food is more important for shedding excess stored fat than the actual number of calories we eat. If we eat in such a way as to keep insulin low, then fat is free to leave our fat cells and be metabolised. If we eat a lot of carbohydrate, the insulin response to the glucose we are eating causes much of that glucose to be converted into fatty acids and stored in the fat tissue. Fatty acids cannot leave the fat cells where they are stored unless insulin drops below a certain level.
What this means is that by eating properly, we don’t really need to know our caloric intake and expenditure, because the body has mechanisms to keep them in balance.