Does Chocolate Build Muscle? Scientists say, "sort of" By Tim Karan, Newser Staff Posted Aug 3, 2011 1:40 PM CDT 4 comments Comments Researchers have discovered a connection between an ingredient in chocolate and muscle activity. (Shutterstock) (Newser) – Can you finally replace your energy bar with a candy bar? Scientists have discovered a connection between chocolate and building muscle, reports the New York Times. Researchers at the University of California in San Diego have found that giving mice a purified form of epicatechin—the main nutritional ingredient of cacao—increased mitochondria in leg muscles. The good news: Mice fed the ingredient—found mostly in dark chocolate—developed increased muscle response even without exercise. The bad news: The effect might not be the same in humans, processed chocolate that isn't in liquid form doesn't contain epicatechin, and you would need to take in only a miniscule amount—about half of one square of a normal candy bar—to see results. “More is not better,” says one study author. “More could lessen or even undo [health benefits]."