What does "overdrive" mean?
"Overdrive" is a noun meaning a state of excessive or intense activity, usually at a level that is not healthy or sustainable. In the case of this video, the speaker says "too much, too often, and things can go into overdrive" to mean that frequently consuming unhealthy amounts of sugar can cause the brain to go into a state of excessive activity, which is quite detrimental to the body. "Go into overdrive" is an expression commonly used to express the above idea. Ex: The upcoming deadline caused the workers to go into overdrive. Ex: I went into overdrive during my exam season. It was very stressful.