There’s a reason you find yourself snacking in the break room so often at work. It turns out that mental work can deplete people of energy, causing their bodies to crave a re-boot—often in the form of food. However, a small new study reveals that a good way to combat the office munchies is exercise.
It may seem counterintuitive, but emerging research is suggesting that exercise actually makes people feel less hungry, possibly due to better regulation of the hormones associated with hunger. In a recent study, published in the journal Medicine & Science in Sports & Exercise, researchers found that people who exercised after doing mental work—like the work we all do at the office each day—ate fewer calories compared to people who did mental work and then remained sedentary.
In the study, researchers randomly assigned 38 college students to either complete a graduate entrance level exam and then spend 15 minutes resting, or complete the exam and spend 15 minutes doing high intensity interval training (HIIT) on a treadmill. The men and women also separately spent 35 minutes relaxing as a control condition. Afterwards, the men and women in the study were told they could eat as much pizza as they wanted.
The researchers found that the people who did mental work and rested ate an average of 100 calories more than when they simply relaxed, suggesting that working our brains expends energy and makes us hungry. Conversely, the people that exercised after mental work didn’t eat more calories, even though they used more energy working out. “Exercise has the ability to increase available fuel sources in the body that may signal to the brain: ‘Here is the energy source I need, I don’t need to replenish it through food,'” says study author William H. Neumeier of the University of Alabama at Birmingham.
More research is needed to understand why exercise might combat hunger pangs, but Neumeier suggests it may be due to its effect on hormones like ghrelin, which can increase hunger. That could explain why people often don’t want to eat immediately after exercise, he says: exercise might be enough of a reward.
“Perhaps it’s the distraction that buffers the desire for food,” he says. “I think this will be highly applicable to a number of individuals who perform sedentary tasks that are mentally demanding but not physically demanding.”
The study sample is very small, but it’s not the first to look at the connection between work and eating more food. Similar studies will need to be done to determine how great a role exercise plays in keeping appetite in check, as well as how much exercise is needed to curb hunger.