Pop Quiz: The 2 PM slump is often triggered by a crash in what physiological element?

A) Decreased serotonin levels.
B) A rapid drop in blood glucose after lunch.
C) A sudden release of melatonin.
D) Reduced exposure to blue light.

The "2 PM slump" is a combination of your body’s natural clock and the way it processes your midday meal:

The Blood Sugar "Crash"
When you eat a lunch high in refined carbohydrates (like white bread, pasta, or sugary drinks), your blood glucose levels spike rapidly.
- Insulin Surge: In response, your pancreas releases a large amount of insulin to move that sugar into your cells.
- The Dip: This surge can sometimes be too effective, causing your blood sugar to drop below its normal level. This rapid decline is what causes the sudden onset of fatigue, irritability, and "brain fog".

The Circadian Connection
While blood sugar is the primary "trigger" for the crash, it is reinforced by your circadian rhythm. Most people experience a natural dip in alertness and a slight drop in core body temperature between 1 PM and 3 PM, which signals the brain to rest.