THIS! I saw Dr. Avena (the voice in this video) at OAC #YWM2013 and she was amazingly informative. WATCH.
As the video shows, the key player in the reward system of our brain — where we get that feeling of pleasure — is dopamine. Dopamine receptors are all over our brain. And doing a drug like heroin brings on a deluge of dopamine. Guess what happens when we eat sugar?
Yes, those dopamine levels also surge — though not nearly as much as they do with heroin. Still, too much sugar too often can steer the brain into overdrive, the video says. And that kickstarts a series of "unfortunate events" — loss of control, cravings and increased tolerance to sugar. All of those effects can be physically and psychologically taxing over time, leading to weight gain and dependence. The takeaway is pretty clear: If you're sensitive to sugar and inclined to indulge in a supersugary treat, do it rarely and cautiously. Otherwise, there's a pretty good chance that your brain is going to start demanding sugar loudly and often. And we're probably better off without that extra voice in our head.