Toxicological trivia on Set. 03, 2009 :"More appropriate would be to call "stimulant drinks" rather than nowaday name of  energy drinks, since":
a) These drinks are designed to increase a user’s mental alertness by the addition of caffeine;
b) The meaning of energizing is not clear, is misleading;
c) The two options together are correct.

Answer c. See our monograph in Spanish: Comments about the so-called energy drinks .Read also in Wikipedia: Energy drink