When I’m in my fitness groove, getting plenty of exercise, I’m the picture of good nutrition. I gravitate towards colorful fruits and vegetables, lean sources of protein, and whole grains — and easily pass up junk food and sweet treats, or just enjoy small portions once in a while.
On the other hand, when I slip into a fitness rut and am less active than normal, I tend to fall prey to my favorite less- nutritious foods, if they’re available: mac-n-cheese, tapioca pudding, and potato chips, just to name a few.
I’ve seen the same behavior patterns in my clients. Is it a coincidence that healthful eating habits seem to go hand-in-hand with regular exercise? I’ve always had a hunch the two were connected — and, sure enough, a recent study points in that direction.
Researchers conducted a literature review and concluded that exercise enhances the brain’s capacity for inhibitory control — the ability to control impulsive behavior — so overeating is less likely. I’m guessing there may also be a psychological component — “I’m putting a lot of time and effort into my workouts — I don’t want to counteract the benefits by eating poorly.”
We already know that that exercise stimulates beneficial changes in brain structure and function:
- Regular exercise — like walking — promotes growth of new brain cells and increases in brain volume, which translate into improved brain function and reduced risk of dementia.
- Exercise also increases the number of connections within the brain — particularly in the gray matter and prefrontal cortex, the area responsible for executive functions like judgment, problem-solving, predicting, planning, and, as it turns out, inhibition, or impulse control.
- In addition to boosting inhibitory control, researchers say regular exercise also makes the brain more sensitive to signs of fullness, helping control appetite and prevent overeating.
- From doughnuts in the break room, to potluck luncheons, to family gatherings, the temptation to eat when we’re not hungry is everywhere. A powered-up capacity for controlling inhibition could help us say, “no, thank you.”
- Long-term well-being depends on our ability to successfully navigate daily obstacles. Because the exercise-enhanced prefrontal cortex governs other executive functions like problem-solving and planning, in theory we should be better-equipped to come up with solutions when a potential obstacle pops up.
- After years of yo-yo dieting, many people lose their awareness of the body’s hunger and fullness signals. If exercise makes the brain more sensitive to satiety signals, we can expect to get better at listening to our bodies at mealtime — and putting down our forks when we’re no longer hungry.
- Ratey J, Hagerman E, Spark: The revolutionary new science of exercise and the brain, Little, Brown, and Company, 2008
- Catharine Paddock PhD. “Exercise May Encourage Healthy Eating Via Brain Changes.” Medical News Today. MediLexicon, Intl., 24 Nov. 2011. Web. 8 Jun. 2012. http://www.medicalnewstoday.com/articles/238191.php
- Voss M, Prakash R, Erickson K, et al. Plasticity of Brain Networks in a Randomize Intervention Trial of Exercise Training in Older Adults, Front Aging Neurosci. 2010; 2: 32. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2947936/?tool=pmcentrez
