It’s about that time again. Right around three or four p.m. your eyelids start to droop a little. Your concentration wanes and your head feels heavy. The time is ripe for your afternoon slump, so you head to the office kitchen for sugar and caffeine to make it through the rest of the day.

But drop the doughnut and grab a hard-boiled egg instead; a new study published in the journal Neuron found that we should nosh on a piece of protein if we want to perk up. The secret to protein’s success as an anti-sleep agent is its ability to activate brain cells called orexin (o-REX-in) cells. Orexin cells produce a stimulant that makes us energetic and triggers the body to burn calories. If the cells’ activity decreases, so does ours.

But sugar — the main ingredient in that chocolate-dipped doughnut — slows the function of energetic orexin cells. This could be the culprit behind your overwhelming urge to take a post-lunch siesta.

Some solid sources of protein to keep the snoozes at bay include low-fat yogurt, cheese, nuts, chicken breast, lean beef, beans and of course, the affordable egg. Try to sneak in protein with every meal and snack to elevate energy levels throughout the day, beginning with breakfast.

Adults should aim to get 10 to 35 percent of their calories from protein, depending on specific needs and activity level. Women should eat at least forty-six grams of protein a day, and men should get at least fifty-six grams a day. Considering a boneless, skinless chicken breast packs a whopping 30 grams, getting enough protein shouldn’t be a problem.

So next time you feel the afternoon slump sneaking up on you, avoid the gravitational pull of glucose and choose protein instead. Your brain … and body … will thank you for it.