Dark chocolate
The flavanols in chocolate may reduce LDL oxidation, inflammation, and improve arterial blood flow, which may boost your energy levels. In one study, a group of adults with chronic fatigue syndrome were given 1.5oz of 85% cocoa dark chocolate daily for eight weeks. After eight weeks, the individuals reported less fatigue without weight gain.
The cacao bean is also chock-full of health-boosting compounds, and is also referred to as the "food of gods." Theobromine and phenethylamine are two compounds in chocolate that are associated with serotonin, the "happy" chemical.
Chocolate with the greatest amount of non-fat cocoa solids will provide the most antioxidants, while milk chocolate, chocolate syrup, and white chocolate rank the lowest in flavonoids (antioxidants). Choose unsweetened cocoa powder or chocolate with at least 72% cacao solids, and preferably Fair Trade.