Q: If I eat dessert after lunch, I’m in such a slump an hour later that I hardly can keep my eyes open. Is this happening because my blood sugar drops too quickly, or is there another reason? — Linda, Monroe, Mich. A: Dessert after lunch buys you a ticket on the glycemic roller coaster. For a while, that molten fudge cake may give you the energy of a hamster spinning its wheel on overdrive. Soon, your blood flow starts to divert from your muscles and brain to your gut. An hour later, your blood sugar crashes, and you’re ready for a siesta, pronto.
But it’s probably not all due to dessert. If your entire lunch is heavy with carbohydrates, there’s more going on. A carb-rich meal raises your levels of tryptophan, an amino acid that, among other things, stirs up your body’s favorite sleepytime hormone, melatonin.
