As far as classic aphrodisiacs go, chocolate is about as close to perfect as they get. Everyone knows the old semi-urban legend that chocolate has chemicals in it that simulate being in love (they're called phenylethylamine and serotonin, which are mild sexual stimulants and mood boosters), but the benefits chocolate has in store for your sex life don't end there. Dark chocolate is also rich in antioxidants and high in caffeine, two ingredients that can increase blood flow and jump-start the libido. Moreover, there's a unique sensual aspect to eating chocolate. A BBC study also found that participants who let chocolate melt on their tongues had higher pulse rates, as well as brain activity similar to that experienced during passionate kissing.
This evidence doesn't mean that all chocolate is going to do the trick. In order to get the right boost, you've got to choose pure, dark chocolate -- eating a huge slice of devil's food cake will just put you in the mood for an afternoon nap. Milk or white chocolate may satisfy your sweet tooth, but the added fat and sugar can slow you down. In order to experience the benefits without the added calorie load, to go for the darkest, least-sweetened chocolate possible.