Stress impacts our bodies in numerous ways, from tension headaches to trouble sleeping. It also affects our appetite: On some nights before a big test or work presentation, we can go through a bag of Cheetos or a pint of Ben & Jerry's in no time. But in other nerve-wracking situations, we lose our appetite completely. What gives? Turns out there are both psychological and physiological factors at play.

Where’d My Appetite Go?

Stress Causes Overeating and Loss of Appetite

The two seemingly contradictory responses come down to a simple distinction: Are you experiencing acute stress—the kind that elicits a fight or flight response—or is it something more chronic?

Our ancestors often had to make split-second decisions to stand their ground or flee as fast as possible—like when that bear smelled the delicious food they were cooking. But even in our cushy modern world, there are plenty of triggers that can spike our anxiety and elicit that same reaction. (If you’re a city dweller, just think of any close calls you’ve had with cabs when trying to cross the street.)

In these moments, the body releases adrenaline, which ultimately gives us a boost of energy and slows down a number of other body processes, including digestion, says Matt Kuchan, Ph.D, a senior research scientist at Abbott. Specifically, adrenaline slows peristalsis, the process that moves food through the digestive tract, which means you’re less likely to feel hungry.

Why Can’t I Stop Eating?

While today’s world isn’t full of threats that provoke a fight or flight response, we still face plenty of stressors. In fact, 75 percent of Americans experience regular stress, according to a survey by the American Psychological Association. The same survey found that one in three Americans turns to food when stressed (nope, you're not the only one).

“We wouldn’t stress eat if it didn’t work,” explains Susan Albers, a psychologist at the Cleveland Clinic and author of the forthcoming book 50 More Ways to Soothe Yourself Without Food. “It makes us feel better only temporarily.” One study, for example, found that chocolate boosted people’s moods, but only for three minutes. Immediate effects of chocolate on experimentally induced mood states. Macht M, Mueller J. Appetite, 2007, May.;49(3):0195-6663.

Plus, long-term stress leads to increased levels of the hormone cortisol in our bodies. A number of studies show that cortisol entices us to eat more, especially comfort foods. CRH-stimulated cortisol release and food intake in healthy, non-obese adults. George SA, Khan S, Briggs H. Psychoneuroendocrinology, 2009, Oct.;35(4):1873-3360.
Occupational burnout, eating behavior, and weight among working women. Nevanperä NJ, Hopsu L, Kuosma E. The American journal of clinical nutrition, 2012, Feb.;95(4):1938-3207.
These high-calorie, high-fat foods are aptly named: One recent study found that women who consumed comfort food had a decreased perception of stress. Comfort eating, psychological stress, and depressive symptoms in young adult women. Finch LE, Tomiyama AJ. Appetite, 2015, Jul.;95():1095-8304. That result is thanks in part to the dopamine that gets released in our brains when we eat these finger-lickin'-good foods. The problem is we need to eat more and more comfort food to achieve that dopamine “high” over time. Dopamine D2 receptors in addiction-like reward dysfunction and compulsive eating in obese rats. Johnson PM, Kenny PJ. Nature neuroscience, 2010, Mar.;13(5):1546-1726.

Your Action Plan

Eating Pizza Whether you speed dial Papa John's or can't fathom taking even a bite of pizza when stressed, the solution is similar: We all need to relax. It may be easier said than done, but learning to turn down our individual stress dials as much as possible can play a big role in our appetite's response to stress.

If you tend to overeat, try to replace that bag of chips with something soothing that's not food-related, like a quick phone call with a friend you haven't talked to in a while. You can also try practicing deep breathing or simply stepping outside for a walk to clear your mind.

And if you notice you've lost your appetite, it may be helpful to plan meals—what you'll eat and when you'll eat it—in advance, Albers says.

Overall, when it comes to stress-reducing techniques, it's better if you can work them into your everyday life, rather than use them in a moment when things are getting out of control, says Amy Shah, M.D., a doctor in private practice in California.

One tip: Start your day with a 10-minute buffer, Shah recommends. When you get up, take a few minutes for a quiet activity you really enjoy, like meditating, stretching, or journaling. “When the first thing we do in the morning is reach for our phones, it’s easy to let stress open our day,” Shah says. “When you ease in, there’s a big difference in the amount of stress you experience.” Plus, having an enjoyable morning ritual is also a great trick to keep you from hitting the snooze button.

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