It sounds like you have a high likelihood of developing an eating disorder if you continue this pattern, so, it's great that you see this behavior as a problem at this point and want some help as to how to put a stop to it. Eating disorders are the most life-threatening psychiatric disorder with about a 10 percent mortality rate.
In addition to being potentially fatal, eating disorders can be very hard to cure and can create a lifetime of suffering, both physically and emotionally. In order to pull yourself from the brink, first you must be willing to give up your obsession with calorie counting, something that I'm sure will not be easy for you to do, but is the first step in breaking your disordered eating behavior and cultivating a healthier relationship with food.
Your preoccupation with calories is the direct result of your enslavement to a deprivation mentality: when you restrict, you become completely obsessed with the object of your restriction. Let's face it, we always want the things we can't have and the more we tell ourselves we can't, the more we want...craving and lust can only be created by that which is forbidden.
If you want to free yourself of all the energy you spend thinking about food, start allowing yourself to eat in response to your physical hunger and give your body what it wants, even if what it wants is a piece of pizza. Yes, I'm sure that scares you to death, because you start to think that if you let yourself eat that pizza there's no end to what you would consume. Or perhaps you worry that you'll immediately gain weight. The truth is, you won't immediately gain weight, and, in fact, you are more likely to gain weight by reducing your caloric intake persistently because your metabolism will slow down in order to adjust to your limited food intake.
The key is to really feed yourself and listen to your hunger and your appetite on all levels (physically, emotionally and mentally) instead of objectifying yourself by turning yourself into a human calculator. In doing so, you will liberate yourself from the fixation with food, and free up your energy and time to invest in far more meaningful and worthy pursuits.
Perhaps you might find yourself a bit anxious and unnerved by this liberation; maybe in a way it's easier to narrow your life focus to calories and consumption. If that's the case, you aren't alone, as many women find it easier to turn their attention to their bodies than to try to address their internal struggles, engage their desires, or think about what it is that they are really hungry for in their lives. But I assure you, if you can manage to work through the angst instead of forestalling it with your superficial fixation, you will find yourself on much more solid ground because you will develop some vital resources that will increase your capacity to cope with life instead of retreat from it.
Of course, at any point along the way, I would encourage you to seek help from a skilled professional if this process proves too difficult to tackle on your own.
While keeping an eye on your weight and food intake is normal, preoccupation with calories and food is not. You don't believe that you have an eating disorder, but it sounds like there is some anxiety or obsession regarding food and calories.
I would recommend asking yourself a few questions. Is my weight considered healthy for my height (refer to Body Mass Index, BMI, charts online)? Does my weight yo-yo? Do I binge eat? Do I purge by vomiting, laxatives or exercise when I feel guilty for over-eating? Do I spend an hour or more a day counting calories or checking my weight? If you answered "yes" to any of these questions, you may in fact have an eating disorder and would benefit from a consultation with a psychiatrist or psychotherapist who is familiar with these illnesses.
If you answered "no," but still feel that you are too focused on calories, try altering some of your food or weight related routines. For example, weigh yourself no more than once a week. If you are using a book or a website to count calories, give the book to a friend or remove the bookmarked site from your web browser.
While this may sound simplistic, chances are that you will notice yourself becoming anxious when you are no longer checking your weight or calories. Now comes the hard part. Sit with that anxiety and resist the urge to check. Eventually the anxiety will decrease on its own, without you having to count calories. With time, as you become less reliant on calorie counting and weigh ins to calm your anxiety, the food-related obsessions will also decrease. Gradually, you may find that you just don't think about it so much anymore.
If, however, you feel an irresistible urge to count calories and can't stop, it may be time to consult with a psychiatrist or therapist for help.