Funny tees with sayings like “I run for pizza” or “I run because I really like beer” sum up the way many of us think about the relationship between food and exercise. Who among us hasn’t pictured the delicious snack waiting for us after a killer workout, for example? But what happens when our exercise routines cause us to consistently overeat? Many of us typically associate a regular fitness practice with healthier eating choices but the relationship between working out and overeating has both biological and psychological roots that may surprise you.

Can exercise make us eat more than we truly need? Adding new challenges into your current routine can indeed cause our bodies to bump up our appetites. “For every 10 calories we burn, we’re expected to crave at least 3 calories – a biological compensation mechanism that ensures we remain properly fueled.” But some people tend to overcompensate for the number of calories they burnt thru exercise by consuming “11 or more calories for every 10 calories burned”, says endurance trainer Matt Fitzgerald, author of Diet Cults and Racing Weight. The reason? A combination of physical and psychological forces—some of which we’re entirely unaware.

In many cases, “it’s reward psychology at play,” Fitzgerald says. “You see this more with beginners who aren’t intrinsically motivated to exercise; they simply don’t love it. Newer people, for whom an activity itself isn’t rewarding, may choose to reward themselves with a food treat; eating more than they normally would, or eating foods they would otherwise avoid.” Even if you have avoided the pitfall of food rewards, we sometimes overestimate the number of calories burned during exercise while underestimating the calories taken in. This can happen whether we’re prone toward overeating or not. As one study showed, subjects trying to lose weight reported eating 47 percent less and working out about 51 percent more than they actually ate and exercised, meaning we might be regularly overcompensating for what we’ve burned.

Biology of a Post-Workout Binge
Research into how exercise might trigger urges to overeat pegs the blame on biological factors. For certain people, especially the obese, challenging bouts of exercise cause massive neural activity in brain regions responsible for food reward and cravings. That said, the more lean you become and the more accustomed your body grows to regular workouts, the less powerful those urges may be. Studies investigating the brain activity of fitter, leaner folks show their food-reward centers respond less aggressively to images of tasty edibles.

Registered dietician and Greatist Expert Erica Giovinazzo reminds us that letting ourselves get too hungry is a guaranteed setup for a binge. “Whether you’re working out or not, you never want to be completely starving at any point in the day. When that happens, we tend to eat a lot more than we normally would – mainly because eating is as much mental as it is physical.” Being ravenous makes us eat faster, leading us to miss out on satiety cues which normally take 15 minutes or more to kick in.

Giovinazzo’s advice? Eat more mindfully (try putting down the fork a few times during your meal or chewing a little longer), portion out your meal like you would if you weren’t famished (chances are, the amount you normally eat should still satisfy you), and stand up mid-meal if you can (sometimes we don’t register how full we are until we get up from the table).

In closing – Hunger is the body’s way of asking to be refueled, so don’t ignore a rumbling stomach, particularly if you’ve recently started working out or increased your intensity in your exercise routine. Try to tune in to the difference between physical hunger and the emotional desire to eat, and hang in there as you learn to accommodate new habits. Opting for more fruits and veggies will help promote feelings of fullness, and staying fueled and hydrated throughout each day can also help with binges.

When it comes to getting a handle on emotional eating, it’s worth remembering that forcing ourselves to do workouts so agonizing that we look to food treats as rewards will most likely fuel an unhealthy cycle of emotional overeating. So find the activity you love, take your favorite class, workout with a friend, or create a jammin playlist to fuel your workout sessions.  Once we get fitter and exercise becomes its own reward, the physical and emotional need to overeat often diminishes.

Greatist, 8/2014