Chocolate doesn’t have to be a reason for weight gain believes neuroscientist Will Clower. In his book Eat Chocolate, Lose Weight, he explains how eating a piece of dark chocolate 20 minutes before and five minutes after a meal can cut your appetite by an impressive 50 percent. According to Clower, this is because chocolate triggers the hormones that tell your brain “I’m full.” However, remember that this applies to cacao-rich dark chocolate only. Milk chocolate would raise your blood sugar levels and leave you craving the stuff even more.