A Healthy Chocolate Bar?

The average American consumes 11½ pounds of chocolate a year. That means 11½ pounds of sugar and fat. It's a treat most physicians tell their patients to eat in moderation.

One candy maker wants that advice to change. Mars Inc., is launching CocaVia, a line of dark chocolate treats injected with liquid canola plant sterol. Sterols are plant-based chemicals that studies show trick the body into lowering cholesterol levels. Mars says that two servings of the chocolate should be eaten daily for maximum benefit.

"Good Morning America" contributor Dr. David Katz has been conducting a study at Yale University on the health effects of chocolate.

The Yale study, which is funded by Hershey, used ultrasound technology and sophisticated measurements to assess the effects of eating dark chocolate on 45 moderately overweight adults. The study also measured participants' blood pressure before and two hours after eating two servings of dark chocolate. Sure enough, after consuming the dark chocolate, which is high in antioxidants, their blood pressure dropped. Dark chocolate also helps blood vessels dilate which allows blood to flow more freely.

But that does not mean everyone can consume as much dark chocolate as they want?

"Chocolate remains a concentrated source of calories and sugar and too much of those things will seriously offset any health benefit," Katz said. "Milk chocolate doesn't work because it's high in saturated fatty acids that harm blood vessels and the overall health of your heart … So don't go overboard, but switch to dark chocolate and you can really have your cake and eat it too."

People should look for chocolate that has a cocoa content of 60 percent or higher, Katz said.

Katz said that dark chocolate has 50 percent more cocoa than milk chocolate and the CocaVia bars are "pretty much the same." The main difference is the plant sterol, but that will not work to bring down cholesterol right away.

"It takes weeks, months of regularly eating these bars to make that happen," Katz said. "You would need to cut that out of your diet somewhere else for the cholesterol benefits to trump the weight gain from regularly eating chocolate."

Katz said that CocaVia bars are example of "functional foods." The manufacturers purposely added a healthy nutrient to the product. He said he expects more similar items in the future.