Energy drink
An energy drink is a type of drink containing stimulant compounds, usually caffeine, which is marketed as providing mental and physical stimulation (marketed as "energy", but distinct from food energy). They may or may not be carbonated and may also contain sugar, other sweeteners, or herbal extracts, among numerous possible ingredients. They are a subset of the larger group of energy products, which includes bars and gels, and distinct from sports drinks, which are advertised to enhance sports performance. There are many brands and varieties in this drink category.Energy drinks have the effects of caffeine and sugar, but there is little or no evidence that the wide variety of other ingredients have any effect. Most effects of energy drinks on cognitive performance, such as increased attention and reaction speed, are primarily due to the presence of caffeine.