Food Coma? Yes, there is such a thing as a Food Coma

Your food coma isn't all in your head.

The funny way to describe the sluggish feeling you get after overindulging on the buffet line is actually a legitimate medical condition doctors call postprandial somnolence.

"It's real. If the meal consumed is large enough, one can go into a food coma due to changes in circulation," says Dr. Lisa Young, a nutritionist.

Once the grub hits your stomach and activates the gastrointestinal tract, blood flow shifts from the muscles and the brain into the stomach and intestines to aid digestion. So when there's less blood in the brain, the feeling of tiredness kicks in.

And certain types of foods can trigger this faster than others.

Meals high in carbohydrates have a high glycemic index, which means they release sugar into the bloodstream quickly. This results in an increase in the hormone insulin, which triggers chemicals in your brain like serotonin that leave you feeling drowsy.

"Solid foods like meat may have more of an effect than liquids," says Young.

Too much protein can also lead to a food-induced snooze fest. A recent study by the Scripps Research Institute involving fruit flies found that the flies that consumed the most protein slept the longest.

So if you want to fight your next food coma, try eating more small meals, and opt for low-glycemic index carbs like whole wheat bread, brown rice and oatmeal.

You also might want to refrain from ordering a glass of wine or beer, Young advises. Since alcohol is a sedative, it'll only make you more tired.