Contrary to popular beliefs that eating sugar-sweetened foods lift up low spirits a new study suggests that sugar can worsen your mood. Researchers discovered that sugar increases tiredness and lowers alertness within an hour after its consumption. The idea of a sugar rush -- sudden gush of energy after the consumption of sugar -- is a myth said the study published in Neuroscience and Biobehavioural Reviews journal. The idea that sugar can improve mood has been widely influential in popular culture so much so that people all over the world consume sugary drinks to become more alert or combat fatigue