Diet - caffeine
Caffeine is widely consumed. It is found naturally in the leaves, seeds, and fruits of more than 60 plants, including tea leaves, kola nuts, coffee, and cocoa beans. It is in coffee, tea, chocolate, cocoa and some colas.
Caffeine is frequently added to over-the-counter medications such as pain relievers, appetite suppressants, and cold medicines. Caffeine has no flavor and can be removed from a food by a chemical process called decaffeination.