What's trending, explained.
What's trending, explained.
Reaching for a snack before bed may carry a bigger cost than previously understood, according to new research published in the journal Clinical Gastroenterology and Hepatology. In a study of nearly 200,000 adults, people who reported eating late at night had a nearly 40% higher risk of developing metabolic dysfunction-associated steatotic liver disease (MASLD) — the condition formerly known as fatty liver disease — than those who did not, and a nearly 30% higher risk of cirrhosis, severe liver scarring.
The findings draw on two long-running US health studies, the Nurses' Health Study and the Health Professionals' Follow-Up Study. Co-authors include Robert Wilechansky, MD, a hepatologist at Oregon Health and Science University and Massachusetts General Hospital in Boston, and Andrew McHill, an associate professor and sleep and circadian physiologist at OHSU.
The proposed mechanism is timing, not just calories. The liver is closely synchronized with the body's circadian rhythms, and eating at night — when the internal biological clock is promoting sleep — appears to reduce how efficiently the body metabolizes food. McHill noted that earlier research has repeatedly shown the timing of behaviors such as sleep, eating, and exercise matters for health, and that animal studies identify the liver as one of the organs most vulnerable to misalignment between eating and sleep timing.
This study adds to a growing body of evidence that when you eat may matter alongside what and how much you eat. It arrives at a moment of heightened public interest in chronobiology: a separate 95,000-person study published in PLOS Medicine in September linked sleep architecture — the balance of deep, light, and REM sleep — to disease risk across dozens of conditions, pushing the conversation from "get eight hours" toward the mechanics of how the body spends the night.
The scale of the new study is its strength: nearly 200,000 participants across two established cohorts, published in a peer-reviewed gastroenterology journal, with a plausible biological mechanism behind the numbers. The authors frame their conclusion carefully, writing that the findings support confining calorie intake to several hours before bedtime — though they emphasize the evidence is still preliminary.
There are real caveats. The study is observational and based on broadly defined, self-reported eating data, so it cannot prove that late-night eating causes liver disease — other factors could contribute. The researchers themselves caution that it is too early to recommend a specific time to stop eating. One thing the study does not do is offer medical advice: if you are concerned about your liver health or eating patterns, consider talking to a healthcare professional rather than redesigning your meals around a headline.
The research team is already moving to the next step. Wilechansky is part of an OHSU team now recruiting for a study that will monitor eating behaviors directly and test whether shifting meals earlier improves clinical measures of underlying fatty liver disease — the controlled follow-up the current observational findings need.
For the public conversation, expect late-night eating to join intermittent fasting and meal timing as one of the contested frontiers of nutrition science. The broader direction is clear: circadian-aligned eating — matching meals to the hours the body expects them — is becoming a serious research program rather than a wellness fad. The new study is a starting point, not a verdict, and its authors are treating it that way.