"Some say that eating chocolate is better than kissing, and scientists have dutifully tested this hypothesis . . . In 2007, a team led by Dr. David Lewis recruited pairs of passionate lovers, whose brain activity and heart rate were monitored first while they kissed and then while they ate chocolate (separately). . . although kissing set the heart pounding, the effect did not last as long as [eating] chocolate. The study also showed that when the chocolate started melting, all regions of the brain received a boost far more intense and longer lasting than the brain activity measured while kissing."
"Stuff matters; exploring the marvelous materials that shape our man-made world." by Mark Miodownik, 2013. p.86.