The world's most expensive piece of chocolate, from Knipschildt Chocolatier, is a $250 dark-chocolate truffle with a French black truffle inside. Fortunately, you don't need to spend big to get big muscles from dark chocolate. Turns out that in addition to its blood-pressure-lowering, cavity-fighting, heart-loving, blues-chasing powers, a double dose (we advocate 1/2 ounce or less twice a day) every day of dark (not milk) chocolate revs up power stations called mitochondria in each and every cell in your body. That makes your muscles stronger and increases your endurance.

What is it about chocolate? It's packed with flavonoids, a plant-based chemical that's a PRO at ANTI almost everything: antiviral, anti-allergic, anti-platelet, anti-inflammatory, anti-tumor and anti-Alzheimer's. It's also adept at affecting cell-signaling pathways that regulate the growth, proliferation and death of cells. Megasurveys show that folks who eat the most chocolate cut their risk for heart disease by 37 percent, diabetes by 31 percent and stroke by 29 percent.

How much is enough? Our favorite is 70 percent cacao semi- or bittersweet. And no more than an ounce a day, or you'll wander into the dark side of dark chocolate -- too many calories and too much fat. (Make sure it takes the place of other calories, so it doesn't add to your total.) If you want to get some of the benefits and fewer calories, even as little as a quarter ounce a day will help make your heart and other muscles stronger and head smarter. How sweet it is!

Mehmet Oz, M.D. is host of “The Dr. Oz Show,” and Mike Roizen, M.D. is Chief Medical Officer at the Cleveland Clinic Wellness Institute. For more information go to www.RealAge.com.