A Risky Combo for Gut Health

Chronic stress combined with late-night eating may increase bowel problems like constipation and diarrhea and negatively affect gut microbiome health.

Watch out! Your gut doesn’t love the combo of stress and bedtime snacks. A new study highlights that people who eat more than 25% of their calories after 9 p.m. and experience high stress are more likely to have bowel problems.

How Stress and Late-Night Eating Affect Gut Health and Digestion

Chronic stress is known to affect bowel function, sometimes causing diarrhea or constipation. New research to be presented at Digestive Disease Week® (DDW) 2026 suggests that eating late at night may worsen these effects and could also impact gut health and the microbiome (1^✔ ✔Trusted Source
Yes, that late-night snacking is probably messing up your gut

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“It’s not just what you eat, but when you eat it,” said Harika Dadigiri, MD, resident physician at New York Medical College at Saint Mary’s and Saint Clare’s Hospital, and the study’s lead author. “And when we’re already under stress, that timing may deliver a ‘double hit’ to gut health.”

Eating After 9 PM and High Stress May Trigger Constipation and Diarrhea

Researchers analyzed data from more than 11,000 participants in the National Health and Nutrition Examination Survey to examine links between chronic stress, late-night eating and bowel dysfunction. Individuals with a high allostatic load score — the cumulative physiological stress as reflected in body mass index (BMI), cholesterol level, and blood pressure — who also reported eating more than 25% of daily calories after 9 p.m. were 1.7 times more likely to experience constipation and diarrhea than those with lower scores who did not eat late at night.

Bowel Problems and Gut Health: The Surprising Role of Stress and Meal Timing

Similarly, data from more than 4,000 participants in the American Gut Project found that people with both high stress levels and late-night eating habits were 2.5 times more likely to report bowel problems. These individuals had significantly lower gut microbiome diversity, suggesting that meal timing might magnify the impact of stress on the microbiome via the gut-brain axis — the two-way communication system involving nerves, hormones and gut bacteria.

The study was observational, so the findings highlight associations rather than cause-and-effect. Further research is needed to better understand how stress, eating patterns and gut health are connected. Still, the results underscore growing awareness of chrononutrition: how the body’s circadian rhythm impacts the way it processes food.

Dr. Dadigiri is sympathetic to those who reach for late-night snacks after long, demanding days, and as a medical resident, she counts herself among them.

Mind Your Mealtime to Protect Your Gut Health

“I’m not the ice cream police,” Dr. Dadigiri said. “Everyone should eat their ice cream — maybe preferably earlier in the day. Small, consistent habits, like maintaining a structured meal routine, may help promote more regular eating patterns and support digestive function over time.”

Reference:

1. Yes, that late-night snacking is probably messing up your gut – ( https://ddw.org/yes-that-late-night-snacking-is-probably-messing-up-your-gut/)

Source-Eurekalert