You’re sitting at your computer, working hard on a project, and it hits you…I’m hungry. I haven’t done any physical activity to warrant it, but I’m starving. Truth is, we often seek food during or after a focused mental activity, such as studying for an exam or completing work projects. Researchers in neurology have suggested that heavy bouts of thinking drain energy from the brain. The brain has a small ability to store fuel, unlike the rest of the body. The brain senses that it is running low on fuel and may require more calories to keep going and signals bodily hunger- even if you have done nothing physically to burn calories. And therefore, we eat, and eat, and EAT and wonder why we are so hungry.
Scientists at the University of Alabama recently have been experimenting with fighting off post-studying food binges with physical exercise instead of caloric intake. They had students focus on a mental task for 20 minutes then either rest for 15 minutes or exercise in the form of running/walking on a treadmill for 15 minutes. They then measured hunger and how much they wanted to eat (in the form of pizza – yum!). They hypothesized the strenuous exercise would increase the amount of blood sugar and lactate circulating in the blood and improve blood flow to the brain. Because the brain uses sugar and lactate as fuel, they wondered if the increased flow of fuel-rich blood during exercise could feed an exhausted brain and reduce the urge to overeat.
What they found was the exercisers ate significantly fewer calories than they consumed at baseline, while the non-exercisers ate significantly more calories than at their baseline. With factoring in the calories burned during running/walking, they determined that those exercising students actually ate 200 fewer total calories after their brain workouts versus the resting students. While there are some limitations to the study, it’s still a good start in showing the benefits of short bursts of exercise to stave off hunger from intense mental activity. As physical therapists, we are constantly encouraging people to move and often just start a walking program to get going. With this study, even 10-15 minutes of walking may be helpful in fighting off food cravings while you are working. This is a win-win – take in less calories, burn more calories, control weight gain to decrease pressure on your joints, and improve cardiovascular health. We also know from several other neuroscience studies have shown that cardiovascular exercise can enhance memory and learning, promote new neuron cell growth, and protect the nervous system from injury and disease! So, give it a try next time you are working hard and go to reach for that candy bar – instead walk around the building!
Reference:
Neumeier WH, Goodner E, Biasini F, Dhurandhar EJ, Menear KS, Turan B, Hunter GR. Exercise following mental work prevented overeating. Med Sci Sports Exerc. 2016 Sept; 48(9):1803-9.
This article was written by:
Elayne Geba PT, DPT, WCS
Pelvic Floor and Orthopedic Physical Therapist and Women Health Certified Specialist
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