Caffeine offers a quick energy boost, but it also affects your body in a number of ways.

Small amounts of caffeine in the diet can actually have a beneficial effect. In fact, research has shown caffeine can help increase athletic performance, focus, and alertness. On the other hand, too much caffeine may increase feelings of anxiety, disrupt sleep, and irritate the stomach.

Sources of Caffeine
Coffee, one of the most popular caffeinated beverages, is a concentrated source of antioxidants and can be a healthful beverage when not consumed alongside high amounts of sugar. Research has shown that coffee can help reduce the risk of type 2 diabetes, cirrhosis, and even early mortality.

Green tea, which has less caffeine than coffee, is also heavily researched for its antioxidant capacity. Interestingly, in both cases, it seems that the beneficial health effects of coffee and green tea are more likely due to their polyphenol content rather than their caffeine content.

Caffeine is also naturally found in cocoa beans and kola nuts.

Caffeine in the Diet
As you may have guessed, not all caffeine sources are created equal. Energy drinks, for example, can be high in sugar and additives. Large designer coffee drinks can also be high in sugar and can pack over one-third of a day’s recommended calories. Historically, a serving of coffee was about eight ounces, but today, portions of up to 64 ounces are not uncommon. Although coffee has a negligible amount of calories alone, when paired with things like whipped cream, flavored syrups, and chocolate, the calories (and added sugar) can increase significantly and actually lead to inflammation (rather than the anti-inflammatory effects of black coffee).

If you don’t currently include caffeine sources in your diet, there isn’t enough evidence to suggest that you should start. But if you do, you may want to avoid caffeine sources at least six hours before you plan to go to bed so it won’t disrupt your sleep.

Including caffeine in the diet can be very bio-individual – some people look forward to their morning cup of coffee as a relaxing ritual, whereas others find that even small amounts of caffeine can cause jitteriness. Small to moderate amounts of caffeine can be part of a healthy diet, but if you find yourself constantly reaching for caffeine sources to get through your day, you may need to adjust your sleep schedule.