The answer may surprise you... but the reason you crave chocolate is because it tastes good! Besides something sweet on your tongue, something creamy in your mouth, and some calories and fat to ward off any hunger that may occur over the next few hours, it temporarily boosts your blood sugar, and even alters some chemicals in your brain that make you feel better. The caffeine may help you become more alert, and at the same time the serotonin (a neurotransmitter) more calm. Why wouldn't we crave chocolate constantly? It does so much for us!
A better question may be "why do you give into the craving?" or "Why are you constantly focusing on it?"
Let's look at the second scenario first:
If you are trying to lose weight or eat healthier, you may continue to remind yourself that chocolate is "not allowed" on your diet or it's "forbidden" or it's "bad". When you tell yourself that something isn't good for you, even though you like it, you are making yourself want it more. Think about things you were told you could not have as a child. As soon as something was "forbidden" you wanted it more. When you were allowed to have it, it lost some of its appeal.
Let chocolate lose some of it's forbidden appeal and let yourself have some. Not a pound bar. You might not even want to keep it around the house or your office. What if you let yourself buy a tootsie roll every day or a peppermint patty? Is there a reasonable amount of chocolate that you could savor, enjoy, not feel guilty about, and have your craving satisfied?
Perhaps your answer is "no" because some people simply cannot have one piece. "I'll eat the entire bag" they say, or "If I can't have a whole candy bar I don't want just one bite".
If you find a happy medium that works for you, like a few chocolate kisses in the afternoon, you may find your cravings aren't monopolozing your thoughts throughout the day.
Okay, then let's address the other question: "Why are you allowing yourself to give in to the craving?"
Think of some of the impulses we deal with each and every day. What are you craving that you just do not act upon because it's not socially acceptable? What if you would just love to plant a big smooch on that new handsome guy at work? Certainly, you aren't going to do it!
What if you would just love to smack that gum out of the mouth of your coworker who annoyingly insists on chewing as loud as a cow all day long? Nope, you aren't going to give into that either.
If your friend got a brand new designer purse and you were just aching to take it home and make it your own, would you do it? No. Why not... You want it.
Think about other desires you have in your life that you don't act on even though it would feel good in the moment. What stops you? Consequences?
The next time you crave chocolate think about what you really want, how you would feel if you had some, and what the consequences would be. Not sure? Let me give you a little tip: If you eat a 300 calorie candy bar every day for a month, you'll gain three pounds. Ouch. Keep it up and you're looking at 36 pounds a year. Not gaining weight? This means you are eating the same number of calories your body burns, and on the flip side that would mean that giving up the daily chocolate bar would result in a weight loss of 36 pounds a year. Some consequences, eh?
Why DO you crave chocolate. More importantly, what are you going to do about it?