Caffeine is naturally found in many foods and beverages; along with coffee and tea, it’s also found in cocoa, kola nuts, guarana, yerba mate, and over sixty other leaves, seeds, and/or fruits. While there are many sources of caffeine, the source doesn’t matter, it’s the amount that does. Healthy adults can consume between 300-400 mg of caffeine a day, which equates to a little more than 4 8-ounces cups of coffee.