For most people, caffeine is synonymous with coffee. In fact, 70–90% of caffeine consumption in the United States comes from coffee. On average men drink almost two cups of coffee daily. Caffeine can also be found in tea, soft drinks, energy beverages, chocolate, some nuts, and medications.
Caffeine is a natural stimulant. Its main effect is on the central nervous system where it alters brain function, causing a temporary change in perception, mood, consciousness, and behavior.
Contrary to popular belief, caffeine will not cure your hangover. However, research shows that a moderate amount of caffeine can have a beneficial effect on men’s health.