For help in answering these questions, I turned to psychologist Mary Boggiano, Ph.D., at the University of Alabama at Birmingham. She provided incredible knowledge and lab data about bingeing, bulimia and addiction, when I was writing Lying in Weight.

“No, chocolate is not truly addicting,” Boggiano says, “but it can sure as heck feel that way for some.”

Technically, chocolate does not induce a drug-like effect on the brain – at least not in the same way that, say, cocaine and heroin do. If you doubt, know this: scientists have even taken apart the ingredients of chocolate i.e. cocoa, cocoa butter etc. and found that no subjects craved the components when they were presented in different food sources.

The sum of a candy bar is definitely better than its parts.

There’s more. Historically, doctors have used the word, “addiction” to refer to a recurring compulsion by an individual to engage in some specific activity. He or she does this despite harmful consequences to health, mental state or social life. Addictive substances or behaviors (i.e. gambling) breed a tolerance, meaning that greater dosages are needed to produce an identical effect over time. And taking away the addictive substance evokes noticeable, if not extreme, physical withdrawal symptoms.

Chocolate does not produce the classic responses that defines real addiction.

“It's not like you need more and more chocolate each time,” Boggiano says. “And any feeling of "withdrawal" is probably more psychological (a habit) vs. physiological.”

Speaking of physiology, there’s a slew of medical research on what happens in the brain in response to addictive drugs. Simplifying the research, an addictive substance is one that produces a specific effect on a specific neurotransmitter (dopamine) in a specific region of the brain called the nucleus accumbens, a seat of reward -- and ironically, fear.

Chocolate does not do this. Or it at least it does not do it in the same way as cocaine and heroin. Studies show that drugs of abuse stimulate the production of dopamine in the nucleus accumbens. These drugs also keep the stimulation going when the brain is repeatedly exposed to them. Chocolate, too, stimulates dopamine. But the brain eventually down-regulates this dopamine response after repeated exposure to chocolate.

So, what looks like a duck, isn’t a duck – that is, if it's a chocolate duck.

However, no one can deny the pure pleasure and pick-me-up feeling of a nice hunk of a Dove Bar. If this is not addiction, than what is it?

Researchers suggest that chocolate induces a delicious mood state that is so vastly different from the PMS-depressed-like mood state you were in when you bought the Dove Bar in the supermarket. Thus, it is this contrast in states of mind (blah versus ahh) that provides the 'hook' or belief that chocolate is addictive.

Of course, there is the caveat that when an eating disorder involving bingeing is present, this dopamine response in the brain can go awry. But that’s a whole different story; a study by British researchers showed that for those who consider their intake of chocolate excessive, any pleasure experienced is short-lived and accompanied by deep feelings of guilt.

Indeed, chocolate is bittersweet.