Late-Night Snacking May Affect Gut Health
New Study by Resident Physician Dr. Harika Dadigiri Illustrates Late-Night Eating and Chronic Stress May Double Gut Health Risks
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The combination of chronic stress and late-night eating appears to amplify the negative effect on gut health, according to a new study led by Harika Dadigiri, M.D., an internal medicine resident in New York Medical College’s Internal Medicine Residency Program at Saint Mary’s and St. Clare’s Hospital, and presented at Digestive Disease Week in May.
“It’s not just what you eat, but when you eat it,” says Dr. Dadigiri. “We already know stress can affect the digestive system. What was striking was that late-night eating seemed to magnify the effects of stress even further, suggesting a ‘double hit’ to gut health. This pattern was reflected not only in bowel symptoms but also in reduced microbiome diversity.”
For the study, researchers analyzed data from more than 15,000 adult participants from two long-term studies: the National Health and Nutrition Examination Survey (NHANES) and the American Gut Project. In the NHANES study, people with high allostatic load — the cumulative physiological stress as reflected in body mass index (BMI), cholesterol level, and blood pressure — who consumed more than 25 percent of daily calories after 9 p.m. were 1.7 times more likely to report constipation or diarrhea. In the American Gut Project, people with both high stress and late-night eating were 2.5 times more likely to report bowel problems and had lower gut microbiome diversity.
“Many people eat late due to work, long hours, or modern schedules. Our study adds a practical dimension: gut health may be influenced not only by what people eat, but also by when they eat and how stressed the body is at that time,” says Dr. Dadigiri.
Based on these findings, Dr. Dadigiri suggests that clinicians may find it useful to ask patients with chronic bowel complaints about meal timing, not only diet quality, to add another counseling point beyond the standard evaluation, especially for patients with chronic stress or irregular schedules.
Because this was an observational study, showing associations but not proving cause and effect, important next questions for the researchers to explore include whether changing meal timing can actually improve bowel symptoms and microbiome diversity, and whether high-stress groups benefit the most. They also plan to conduct longitudinal studies and controlled trials testing whether meal-timing changes improve gut outcomes in high-stress individuals.
“The message is not that people should feel guilty for eating late,” says Dr. Dadigiri. “A realistic takeaway is that small, consistent changes may help: maintaining a more structured meal routine, making late meals lighter when possible, shifting some calories earlier in the day, and finding practical ways to manage stress. Overall, our study reinforces that gut health is shaped by diet, timing, stress, sleep, and the microbiome together.”
