Reverse an afternoon slump

Scientists call it the postprandial dip, the post-lunch dip or the secondary sleep gate. You call it a face-plant in your keyboard in the middle of the afternoon. No matter how you refer to it, an afternoon slump rarely helps you get ahead. Some research suggests we're hard-wired to have an energy dip between 1 p.m. and 4 p.m. (though no one knows why evolution thought that was a good idea). Fortunately, you can at least compensate for it — and likely lessen it — with these strategies:

Make every meal count. You can't just blame lunch for heavy afternoon eyelids — the post-lunch dip can even hit people who skip that meal. Your energy level is affected by what you do or don't eat the whole day long; try to eat no foods with added sugars, syrups and no grain that is less than 100 percent whole. This keeps your blood sugar more constant, and you more alert.

Try a little caffeine. It helps you sustain afternoon attention, but beware: It also might keep you from going to bed, creating an even worse dip tomorrow morning.

Take a hike. Or just walk to lunch the long way. People in one study felt less afternoon fatigue on days when they worked out during lunch. Regular activity is key; one workout on one drowsy day won't give you afternoon energy all month.

The YOU Docs, Mike Roizen and Mehmet Oz, are authors of the "YOU: Being Beautiful — The Owner's Manual to Inner and Outer Beauty." To submit questions, go to RealAge.com. Distributed by King Features Syndicate.