Most people believe we tend to burn maximum calories during the early hours of the day or when we sleep at night. But researchers reporting in Current Biology have an interesting revelation – when at rest, people burn approximately 10 per cent more calories in the late afternoon and early evening than in the early morning hours or sleep hours.
According to this recent research, the number of calories people burn while at rest, changes with the time of the day. Suggesting the important role of the circadian clock in the way our body’s metabolism functions, the researchers pointed out that people with irregular eating or sleeping habits are more likely to put on weight.
“The fact that doing the same thing at one time of day burned so many more calories than doing the same thing at a different times of day surprised us,” says Kirsi-Marja Zitting of the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital and Harvard Medical School, lead author of the paper, as reported by ScienceDaily.
For the purpose of the study, the researchers examined seven people in a special laboratory. The people who participated in the research were not given any access to phone, internet or even windows – making it impossible for them to find out what time it was or keep track of the day. This was done to determine changes over the course of the day in metabolism.
“Each night, those times were adjusted four hours later, the equivalent of traveling westward across four time zones each day for three weeks”, the ScienceDaily reported.
“Because they were doing the equivalent of circling the globe every week, their body’s internal clock could not keep up, and so it oscillated at its own pace,” co-author Jeanne Duffy, also in the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital, explains, as reported by ScienceDaily. “This allowed us to measure metabolic rate at all different biological times of day.”
The data showed that resting energy expenditure was highest “at circadian phase ~180°, about 12 hours later, in the biological afternoon into evening.”
“It is not only what we eat, but when we eat – and rest – that impacts how much energy we burn or store as fat,” Duffy said. “Regularity of habits such as eating and sleeping is very important to overall health.”
As long as burning calories is concerned, looks like it takes a lot more than just eating clean and hitting a gym.