It’s a hotly contested question in the nutrition world: is breakfast really the most important meal of the day? Experts say that people who eat breakfast are less likely to overeat the rest of the day, but recent studies have found no difference in weight between those who skip their morning meal and those who don’t. In the meantime, skipping meals has become an increasingly popular part of modern life.
Breakfast-eaters tend to have lower rates of heart disease, high blood pressure and high cholesterol, the American Heart Association reported earlier this year, but the group says the science isn’t strong enough to suggest that people who don’t normally eat breakfast should start. On the other hand, some research has even suggested that fasting for longer overnight periods (eating an early dinner, for example) could actually help people lose weight.
Now, a small new study in the American Journal of Clinical Nutrition sheds some light on what really happens in the body when people skip breakfast on a regular basis. People burn more calories on days they skip breakfast, but that the habit may increase dangerous inflammation.
Researchers from the University of Hohenheim in Germany tested 17 healthy adults on three separate days: once when they skipped breakfast, once when they had three regular meals and once when they skipped dinner. Despite the change in scheduling, the calorie content and breakdown of carbohydrates, fat and protein were the same on all three days. (On days with a skipped meal, the other two meals had extra calories to make up for it.) Each day, blood samples were collected frequently from 7 a.m. until 9 p.m. to measure hormone levels, glucose and insulin concentrations, and immune cell activity.
They found that people burned more calories over a 24-hour period when they extended their overnight fast by skipping either lunch (41 more calories) or dinner (91 more calories), compared with the three-meals-a-day schedule. These findings are in line with other studies on time-restricted eating.
They found no difference in 24-hour glucose levels, insulin secretion or total physical activity between the three days. But glucose concentrations and markers of inflammation and insulin resistance were higher after lunch on breakfast-skipping days.
This article originally appeared in Time.com