Sugar Crash

A sugar crash or glucose crash is the term used in American popular culture to refer to a supposed sense of fatigue after consuming a large quantity of carbohydrates, also known as reactive hypoglycemia. It is variously described as a sense of tiredness, lethargy, irritation, or hangover, although the effects can be less if one has undertaken a lot of physical activity within the next few hours after consumption. The alleged mechanism for the feeling of a crash is correlated with an abnormally rapid rise in blood glucose after eating. This normally leads to brisk insulin secretion (known as an insulin spike), which in turn initiates rapid glucose uptake by tissues either accumulating it as glycogen or utilizing it for energy production. The consequent fall in blood glucose is indicated as the reason for the "sugar crash".