As with any food product, the amount and frequency you consume an item matters. Energy drinks are quickly replacing soda as America’s favorite beverage, with 20 billion dollars being spent on these drinks in 2013(Ref 1). The beverages are especially popular with teenagers, with 30-50% of them consuming these drinks on a regular basis (Ref 1). However, daily consumption of energy drinks over the long run can contribute to health problems.
A 2014 Review in the "American Journal of Cardiology" demonstrated the connection between energy drink consumption and cardiovascular issues. The review highlighted that more than 20,000 visits to the emergency room are directly related to energy drink consumption (See Ref 2). Additionally, the review highlighted that most of these cardiovascular complications from energy drinks can be contributed to the high amounts of caffeine in these products.
The Academy of Nutrition and Dietetics recommends that healthy adults consume 200 to 300 milligrams of caffeine or less per day (See Ref 3). One 16-ounce energy drink can contain 160 milligrams of caffeine, almost your daily recommendation(See Ref 4). Some energy drinks even contain as high as 357 milligrams of caffeine per 16 ounce serving (See Ref 4). Overconsumption of caffeine has been linked to insomnia, anxiety, headaches, and jitters (See Ref 4).
Most energy drinks contain ingredients such as taurine, an amino acid, which occurs naturally in meat and fish (See Ref 5). The issues with taurine in energy drinks is the unknown negetive interaction that might occur with other ingredients, specifically caffeine. Little is know about the long-term effects or heavy use of taurine in this context (See Ref 5).
The American Heart Association recommends that adults consume at most, 6-9 teaspoons of sugar per day, depending on gender (See Ref 6). On average, one 16-ounce bottle of energy drink has between 34-60 grams of sugar, or 8.5 to 15 teaspoons of sugar (See Ref 5). Chronic consumption of added sugars can lead to health complications such as type 2 diabetes, obesity, and dental cavities. You should limit your consumption of energy drinks, but if you consume them, choose types with lower amounts of caffeine and sugar free varieties.