Beverages called energy drinks are popular, especially with teenagers and young adults. These energy drinks are advertised to give individuals a higher energy level, to make a person feel more awake, and to boost attention span.
Energy drinks are marketed in different serving sizes and have varying amounts of caffeine. Sodas (also known as pop, colas, or soft drinks) may contain sugar and caffeine, although most sodas contain less caffeine than energy drinks on an ounce-by-ounce basis. As a comparison, an 8-oz cup of coffee has about 100 mg of caffeine (see table). The January 16, 2013, issue of JAMA contains 2 articles discussing the harms associated with energy drinks.