Although thinking hard at work or school isn’t the same as a physical workout, it’s still taxing and tiring. And studies have shown that it actually does increase your hunger. Here’s why it does, and what to do about it (besides eat!).

Does mental work burn calories?

The basic answer is no. One study showed that students given a thinking-task burned only three more calories than students who spent the same amount of time just relaxing. Three calories aren’t going to make a difference to anyone. But what seems to be harmful to you hard thinkers out there, is that even though you’re not burning calories, your feelings of hunger increase. And that often leads to over-eating.

Do you get real hunger from studying or thinking hard?

A recent study in Canada took students and randomly divided them into three groups. One group was told to relax, one group did some simple reading, and the third group was given a complex computer task. When they were finished with their tasks, all were taken to an all-you-can-eat buffet. It turns out, the group with the complex-thinking task consumed an average of 200 calories more than the group who relaxed.

The University of Alabama at Birmingham conducted a second study. To get baseline results, researchers first took undergraduate students and had them all complete the same graduate-level exam. The students just rested after the exam and were offered all the pizza they could eat.

Then the following week, they gave the same students another similarly difficult graduate-level exam. This time, half of the group rested again for 15 minutes after the exam, while the second group participated in high-level exercise. The exercisers ate 25 less calories than they had the previous week where they relaxed. But the group that relaxed again ate 100 calories more this time.

Why do you feel hunger after mental tasks?

The researchers took blood samples before, during, and after the various activities in the first study. Results showed that the difficult-thinking task caused big fluctuations in glucose and insulin levels. Because glucose fuels neurons in the brain, this fluctuation seems to send hunger signals. This causes feelings of hunger, even though the caloric energy spent on the task is almost nothing.

Researchers in the second study took this even further. They determined that the glucose and lactate you produce when you exercise provides the additional energy your brain needs, instead of taking in calories through food.

How to squash the hunger you feel from thinking hard 

As the studies above concluded, after you’ve had some difficult intellectual tasks, a brisk walk or a short bout of any type of exercise may get rid of those hunger feelings.

Take a pause before automatically reaching for a snack. Think about the possibility that you’re not really as hungry as you feel. Then try something else instead to see if that hunger feeling goes away. The snacks will still be there in 15 minutes if you wait a bit, and you may not feel like you need them by then!

Just being aware that you may be feeling hungry when you’re really not may help. Think about your fitness goals, your weight goals, your blood pressure…whatever it is you’re trying to achieve. Thinking about these goals can help your brain override the false feelings of hunger you’re feeling.

If you do decide that you really need to eat, have a snack drawer or stash in the fridge ready to go for these times. Stock it with things that aren’t bad for you—protein is usually your best bet. Nuts, cheese and crackers, a hard-boiled egg, or a Greek yogurt will take care of those hungry feelings.

You can overcome this type of hunger 

Studies have shown that while you don’t burn many calories, intellectual tasks can give you false feelings of hunger.

Try taking a break before heading straight to the snacks, and if at all possible, just move for a few minutes. If you can, take a quick 10-minute walk.

You’ll be surprised how much better—and less hungry—you’ll feel afterwards. Give it a try!