In what food source is the nutrient found?

Caffeine occurs naturally in foods and beverages. It is found in coffee, tea, soft drinks, cocoa, chocolate, and kola nuts. Trimethylxanthine is added to caffeinated sodas during processing. Caffeine is also added to several over-the-counter medicines to increase their effects. Some weight-loss products, pain medicines, and cold remedies contain caffeine.

The caffeine content of coffee depends on the type of coffee bean. Beans from the plant species robusta generally have more caffeine than those from the arabica species. Arabica beans generally produce a more full-bodied flavor. These beans are the ones likely to be found in gourmet coffee shops. The roasting and brewing of coffee also play a part. Contrary to popular belief, darker roasted beans actually have less caffeine. The heat literally roasts out the caffeine.

Here is the caffeine content of certain foods, beverages, and medicines:

How does the nutrient affect the body?

Caffeine acts as a stimulant on the central nervous system. That means it increases the heart rate and blood pressure. The individual may temporarily feel more awake and energetic. Caffeine also acts as a diuretic, which means it works on the kidneys to excrete more urine.