The Blood Sugar Coaster

Your brain runs almost entirely on glucose, and it has no real fuel tank — it needs a steady, even supply. So when blood sugar spikes and then crashes, your thinking crashes with it.

That 3 p.m. fog you blame on a dull meeting? It is often the sugar crash from the white-bread sandwich and soda you had at noon. The energy shot up, then fell off a cliff, and your brain got caught short right in the dip.