When making informed choices about what we eat, some people turn to calorie counts on foods and in turn pay attention to how many calories they’ve burned during a workout. Of course, the jury’s out on whether counting calories even matters, but those who do find these units of energy helpful may be wondering which time of day your body burns the most calories while at rest. Now, thanks to new research, we know.
According to an article published in the journal Current Biology, our bodies burn calories in different amounts throughout the day. As it turns out, our bodies burn 10 percent more calories in the late afternoon and early evening than in the early morning hours.
The study reinforces the idea that our circadian clock helps guide our metabolism and may help to explain why an irregular eating and sleeping schedule may cause people to gain 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 time of day surprised us,” Dr. Kirsi-Marja Zitting of the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital and Harvard Medical School and lead author of the paper, said in a statement.
The study involved having participants stay in a lab without any clocks or clues about what time it was and dictate the times they went to sleep and woke up. Researchers took their temperatures to find out when they were using the most energy while resting.
“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 says. “Regularity of habits such as eating and sleeping is very important to overall health.”