How Stressing About What You Eat Changes How You Digest It

Trigger warning: This article discusses stress around food choices. Those who struggle with an unhealthy relationship with food can visit the National Eating Disorders Association for support. 

In a culture where food is categorized anywhere from "good or bad," to "practically medicinal or ostensibly toxic," deciding what to eat can be a stressful experience. For people with allergies and digestive disorders who have painful or even life-threatening reactions to certain foods, it's even more trying.

Of course, it's only natural to want to fuel ourselves with nourishing food and avoid anything that might make us sick. But being overly stressed about food choices can make us unwell faster than any "bad" food ever could. 

When faced with perceived danger, your body's stress response sets off a cascade of physiological symptoms, from hormone changes to blood sugar shifts.

Our adaptive response to stress may lengthen the time it takes for food to move through the digestive tract, slow the production of digestive secretions, and make the muscle contractions involved in digestion sluggish, says Christine Cherpak-Castagna, Ph.D., a nutritionist and adjunct faculty member at the Maryland University of Integrative Health. 

Acute stress may also temporarily change the composition of the microbiome1, says Marvin Singh, M.D., an integrative gastroenterologist.

This causes food eaten in a stressed-out state to get a less-than-fair chance of optimal digestion.

For example, let's say you eat a big breakfast, and then while driving to work, someone cuts you off, causing some stress. Later, you struggle with indigestion. "Your body felt that stress, and as a result, your motility was altered, and the food that was sitting in your stomach didn't get out of your stomach as fast as it should have. You feel the effects of that." 

For those who have a stressful relationship with food, mindful eating may be particularly useful. 

"Mindful eating encourages individuals to be present—without judgment—through all phases of eating, naturally prompting parasympathetic dominance and, thus, 'rest and digest,'" Cherpak-Castagna says. "This state of calm and relaxation supports optimal digestion."

There's some research to back this up: One randomized controlled trial in the International Journal of Behavioral Medicine found that participants who completed mindfulness-based stress reduction exercises experienced fewer IBS symptoms3 than a control group. Another 2011 study on women with IBS who completed eight weeks of mindfulness training came to a similar conclusion.

Eating healthy (whatever that means for you) is important, but being preoccupied about food choices can do more harm than good. Stress disrupts digestion by slowing gastric emptying and changing the gut microbiome, which can cause nausea, indigestion, heartburn, and stomach pain.