Chocolate is made from the seeds (种子) of cocoa trees (可可树). The seeds come in football-shaped pods (豆荚). A pod is about 15 to 30 centimeters long, 8 to 10 centimeters wide. When you break a pod, you'll find 20 to 60 seeds.
You take out these seeds, cover them up in banana leaves and leave them for about a week. This process is called fermentation (发酵). It is similar to the process of making yogurt. After the fermentation, you dry them, clean them, heat them and break them. Then you get something with a smell of chocolate. It is heated and separated into cocoa butter. When you mix it with milk or sometimes vegetable oil, and sugar, you get different kinds of chocolate.
Chocolate is not a good choice if you want to lose weight, but it is a good source (来源) of vitamins and minerals (矿物质). You should be careful not to eat too much because it may cause some people to have a headache. It can also cause skin problems in some people.
But recent surveys have found that chocolate helps people improve the ability to understand or remember things. It is also said that chocolate helps many people sleep better. We might have to wait for more research, but we all know that we love chocolate!