Why do I crave sweets

Some times the thought of sweets just take over my brain.  I could be sitting watching TV and the thought of a Toll House cookie in the cookie jar just won't let me rest.  All I can do is think is " Toll House Cookie", Toll House Cookie.  The Toll House cookie  marches though my head and I just have to have it.   About.com has an article that says it may be your family tradition to have something sweet after dinner or it could be the serotonin levels in your brain could be low. It explains that serotonin is a brain chemical that makes you feel content and happy.  It is amazing to realize that all these years of being over weight could have been just understanding the way the body works and making better choices in the foods you eat  .