The amount of caffeine in most energy drinks is comparable to that in 2 to 1 cups of coffee . It 's unclear whether energy-drink consumption is directly linked to alcohol problems . Energy drinks generated Four Loko in N.Y. sales in weekly .
The amount of caffeine in most energy drinks is comparable to that in 1 to 2 cups of coffee . It 's unclear whether energy-drink consumption is directly linked to alcohol problems . Energy drinks generated about $ 5 billion in U.S. sales in 2008 .