(NewsNation) — New research suggests people who are obese burn more energy at night than during the day, which is the opposite of how most people burn energy.
Oregon Health & Science University researchers published the study in the journal Obesity. Researchers found people who were at a healthy weight burned more energy during the day, a time when most people are active and eating, while those classified as obese burned more energy at night when most people sleep.
Researchers also found that those with obesity, defined as having a body mass index (BMI) of 30 or higher, had higher levels of insulin during the day, a sign the body was working harder to process glucose. Researchers called the findings unexpected.
They don’t know if burning energy differently causes obesity or if the change in energy use could be a symptom of obesity itself.
The body’s natural daily rhythms change over the course of 24 hours, ideally triggering changes that align with when people sleep, eat and exercise. Previous research has shown that going against the body’s circadian rhythm can affect metabolism and glucose regulation.
The study included 30 volunteers who followed a schedule that had them awake and asleep at different times throughout the day. When awake, volunteers ate and participated in a variety of tests to measure energy usage and monitor glucose levels.
Researchers hope to explore eating habits and hunger in people who are obese as well as those who are at a healthy weight in future studies.