A cup of coffee normally contains approximately 100 mg of caffeine. One caffeinated energy drink of 56 ml contains 200 mg of caffeine. This consistency will provide energy for five hours, as per the report from the Center for Science in the Public Interest. So by estimates, five 5-hour energy drinks would be equivalent to ten cups of coffee.

Kathleen Miller, an energy-drink specialist from the University at Buffalo Research Institute on Addictions said, "Caffeine can be a great thing, at low doses; with the consumption of five 5-hour Energy drinks, however, you move past alert and awake, into the territory of jittery, anxious and heart palpitations."

Caffeine doses higher than 5000 mg can lead to seizures, hallucinations and strokes.

Kathleen Miller said, “Excessive caffeine consumption is also especially dangerous for children and teenagers with low body mass; chemically, caffeine can deceive your body into thinking it is wide awake when what you really need is sleep; this is harmful for young people who need sleep, and for everyone long-term. With repeated use, caffeine can elevate blood pressure and cause prolonged sleep disturbances."

Miller added, “There are certain plant and herbal extracts in energy drinks that count as "dietary supplements, which are legally exempt from regulation; Although these extracts are mostly present in low doses, their effects are unclear and could be potentially harmful”.

Energy drinks might keep you awake. But, no research till date confirms that over-consumption of energy drinks could keep you healthy...