Drop that candy bar: a new study  says the "sugar rush" you've used all these years as an excuse to eat something sweet is a myth.

No, that supposed pop of energy that's supposed to wake you up and give you focus, actually does neither -- in fact, there isn't even even a boost of energy at all, says a team of researchers working out of the Humboldt University of Berlin, and the U.K.'s Warwick University and University of Lancaster.

The scientists looked into 31 studies that included nearly 1,300 participants, and found that not only did that hit of sweet stuff make subjects more tired, it didn't enhance their focus, either.

It didn't even boost their moods.