From late dinners to midnight snacks, sometimes there’s no way around eating later than you might like. But according to a new study published in the journal Cell Metabolism, eating late at night might have some unfortunate and unintended side effects.

Studying The Impact Of Late-Night Eating

The study authors looked at three key factors associated with weight regulation and obesity risk: appetite, energy expenditure (aka calories burned), and molecular changes in fat tissue.

To do this, they had 16 overweight or obese participants follow two meal schedules. The first meal schedule was considered an “early meal schedule,” and the second was the exact same schedule but everything was four hours later (i.e. the early schedule’s dinner was at 5 p.m., and the late schedule’s dinner was 9 p.m.).

Throughout both sets of meal schedules, participants took note of their hunger levels, gave blood samples, and had their temperature and energy expenditure measured. Some of the participants also had adipose (body fat) tissue collected for testing.

All the while, the researchers were very careful to eliminate any compounding variables with protocol, such as sleeping schedules and what the participants were eating.

What The Research Found

Based on the study’s findings, eating late does appear to have some connection to obesity risk, namely in those who are overweight or obese already.

The results showed that when participants were on the later meal schedule, they woke up feeling hungrier, were less effective at burning calories, and had adipose tissue that showed increased fat growth.

As study author Nina Vujović, Ph.D. explains, “We found eating four hours later makes a significant difference to hunger levels, the way calories are burned after eating, and the way fat is stored.”

But since this research only included overweight or obese participants, the study authors say further research is needed to see if these results would translate to the larger population.

Nevertheless, given that we already know eating late at night can disrupt sleep and cause blood sugar spikes, it’s worth avoiding for other reasons if you can help it too.