Caffeine is a stimulant found in many foods and beverages such as coffee, tea, and some sodas.
Caffeine consumption usually causes feelings of alertness, and ninety-eight percent of North Americans consume it in some form((Energy drinks and the neurophysiological impact of caffeine. Persad, L. Department of Physiology, University of Pretoria, Pretoria, South Africa. Frontiers in Neuropharmocology, 2011, Oct;5:116)). Moderate consumption has been linked with numerous health benefits, including improved memory, a speedier metabolism, and better workouts. However, excess caffeine (more than 500mg per day) can have potentially harmful effects on the body.