Many people like to place emphasis on calorie counting for weight loss. Here I would like to explain why it is a myth and should not be used as a means of weight loss.
If you think that say, by eating 1000 calories a day and burn 1500 that you must lose weight, I am about to disappoint you. Your body is smarter than you are, and it will actually fight your efforts by programming you to store more fat if you take this 'energy in verses energy out' approach too far.
Its called the survival rule and works like this - If you cut back your calories, especially those that come from good fats, your body assumes that food is scarce and it goes into stress hormone release (cortisol), immediately storing fat! In order to make sure you don't starve and die, your hormonal system switches begin to use muscle for energy (because stored fat will keep you alive for longer). At the same time it releases more cortisol to help store more fat faster. If you're female, this effect is accelerated because, what if you were to become pregnant?
So if you decide to up your exercise and restrict your calories, not only is food scarce, but now your fighting for your life! After all, why would you be doing so much cardio?
In response, your digestive system will slow down, your metabolic rate will slow and more fat will be stored, because your body will be wondering when it will get a chance to eat again.
This shows the importance of balanced nutrition, and eating the right food, including good fats.
Another way I like to look at the logical, simple reason to avoid calorie counting is this: If I told you to have 1500 calories a day - one visit to a fast food outlet could just about fill this daily intake - do you want to live on one meal a day? I definitely wouldn't want to, and can not see anything healthy or of benefit in doing this!