The midnight snack could have some more consequences than expected, at least for those who are in the habit of indulging in it every evening. A study of 199,155 people found that eating habitually after dinner or at night was associated with a 36% higher risk of fatty liver and 28% higher risk of cirrhosis. Percentages that remain significant even considering body weight, calories, quality of nutrition and alcohol consumption.
The research, published on October 9, 2026 in Clinical Gastroenterology and Hepatology, was coordinated by Robert Wilechansky, a hepatologist at Oregon Health & Science University (OHSU), together with colleagues at Massachusetts General Hospital. The researchers analyzed the eating habits of almost 200,000 American adults, followed for a median period of 16 years, to understand how much the time we eat can affect liver health. And the answer seems to deserve attention.
36% higher risk for those who eat after dinner
The researchers used data from three large American studies, the Nurses’ Health Study, the Nurses’ Health Study II and the Health Professionals Follow-Up Study, which have been collecting information on the health and habits of nurses and other healthcare professionals for decades. Participants had a median age of 59 years and had no known liver disease at the start of the observation. About 29% said they usually ate after dinner or after bedtime.
A rather common habit, therefore, which scholars have compared with that of those who finished eating early. During the observation period, 4,492 new cases of hepatic steatosis associated with metabolic dysfunction (MASLD), more commonly known as fatty liver, and 315 cases of cirrhosis were recorded.
Fatty liver disease is characterized by the accumulation of fat in liver cells and can remain silent for years. In some people it can progress to inflammation, fibrosis and, in more advanced cases, cirrhosis, a condition in which liver tissue is progressively replaced by scar tissue. Among people used to eating in the evening hours, both diseases were more frequent.
The researchers then adjusted the results by considering age, body mass index, diabetes, cholesterol, smoking, physical activity, alcohol consumption, daily calories and overall diet quality. The difference remained: +36% for fatty liver and +28% for cirrhosis. These are relative increases in risk, so it doesn’t mean that 36% of people who snack in the evening will develop liver disease.
Skipping breakfast or eating a different number of meals during the day also initially seemed to be associated with greater risks. Once the other factors were considered, however, these associations were no longer significant. The habit of eating after dinner, however, continued to show a relationship with both pathologies. Also considering night work, the relative increase in the risk of cirrhosis reached 49%.
The liver has a biological clock and also follows meal times
Our liver works around the clock, but does not perform all its functions with the same intensity during the day and night. It has its own biological clock, connected to the circadian rhythms that regulate sleep, wakefulness and numerous metabolic processes. In practice, the body does not necessarily manage in the same way what we eat at eight in the morning and what we consume just before sleeping.
Andrew McHill, a sleep physiologist and co-author of the study, explained in the official communication from Oregon Health & Science University that eating when the body clock is preparing the body for rest can reduce the efficiency with which foods are metabolised.
Some experiments on animals have already shown that the liver is particularly sensitive to the lag between meal times and sleep times. When this balance is repeatedly altered, changes in sugar and fat management can occur. The possible link with hepatic steatosis, therefore, has a plausible biological explanation, even if the mechanisms involved have yet to be clarified.
A scientific review published in eClinicalMedicine examined research on circadian rhythms and metabolic liver disease, finding particularly strong associations for shift work. However, the evidence relating to meal times was still limited.
What time should you stop eating?
Midnight, of course, does not represent a threshold identified by scholars: no one has established that at 11.59pm the liver works perfectly and a minute later it begins to have problems. The questionnaires asked participants whether they usually consumed food after dinner or after going to bed. The time of each snack was not precisely recorded, nor how much time passed between the last meal and sleep.
Consequently, the results do not allow us to establish that eating dinner at 9pm is harmful or that eating something at 10pm automatically represents a danger. Then there is another limitation: the dietary information and diagnoses were reported by the participants. The researchers did not systematically have ultrasounds, blood tests or other clinical investigations to directly verify the state of the liver.
Furthermore, the sample was predominantly composed of white healthcare professionals with a high level of education. A population that does not necessarily represent all eating and working habits. And as regards cirrhosis, the 315 cases recorded in almost 200 thousand people require us to carefully read that 28% relative increase. Cirrhosis remains a much less frequent outcome than hepatic steatosis, and the risk estimate is less precise.
Can anticipating the evening snack protect the liver?
Wilechansky believes that focusing your calorie intake several hours before bedtime could be beneficial for metabolic health. To test this, the OHSU research team is recruiting participants for a new clinical trial. This time the researchers will directly monitor meal times, also through photographic diaries, and will use diagnostic tests to evaluate whether eating earlier can improve liver conditions in people with fatty liver disease.
An important distinction concerns those who already suffer from cirrhosis. The European EASL-EASD-EASO guidelines in fact recommend an evening snack in some clinical conditions, especially in the presence of loss of muscle mass or decompensated cirrhosis. For these people, eating schedules must be agreed with the doctor, avoiding autonomous changes.
For others, the research suggests paying attention above all to the regularity of eating habits, without turning an occasional dessert after dinner into a health emergency. The signal identified by the researchers concerns a behavior repeated over time. To know whether anticipating the snack can really reduce the risk of fatty liver, we will need proof that questionnaires, even after sixteen years, cannot provide.
