Why Do We Crave Unhealthy Foods?

Ever wonder why we seem to crave most the food that's worst for us? Could it be that we literally can't resist it?

That's what neuroscientist Ann Kelly has been studying for more than a decade in her lab at the University of Wisconsin, CBS News correspondent Trish Regan reports.

"In a way, food is like a drug," Kelly says.

In the lab, when a drug-addicted rat thinks it's about to get its morphine fix, the brain lights up. It turns out that when a rat in the lab that's conditioned to like sweets thinks it's going to get chocolate, its brain shows similar activity.

"I hesitate to say there is such a thing as food addiction," Kelly says. "But what we have to keep in mind is that food can affect the brain in a very similar way as addictive drugs."

"This could be the smoking gun," says law professor John Banzhaf. "We could say fat is the next tobacco."

Banzhaf is an architect of anti-tobacco lawsuits who has also sued the food industry. He's been involved in some of the eight suits so far have resulted in settlements or industry changes.

"If we can change the six major fast-food companies so they are providing clear and conspicuous disclosure on their menus of fat and calories and providing health warnings, we will have a dramatic impact on the overall problem of obesity — and it will happen immediately," Branzhaf says.

Not so fast, say critics.

"When you say a food is addictive, what you're really saying is that the obese person is a victim, and you know that's abandoning individual responsibility," says Dr. Elizabeth Whelan with the American Council for Science and Health.

As Anne Kelly continues her research, the lawyers wait, salivating in hopes of that smoking french fry.