There are a million reasons why a person should not eat too much sugar. The shit is terrible for you. However, the hyperactive sugar high is not one of them. It’s totally not a thing. The whole idea came from a VERY flawed study from an Allergist who was essentially pulling things out of their ass. Extensive testing went in to this and in 1995 the American Journal of Medicine published a study showing that the entire concept was bullshit.