Study Finds We Burn More Calories in the Afternoon
Circadian clock affects your sleep, but did you know that it may affect your metabolism too? A recent study suggests people burn more calories at rest at different times of day, in sync with the circadian clock.
Participants in the study included seven people who underwent a sleep study. They were put in a room with no clues about the time outside — including clocks, windows, phones, or internet. They were then assigned times to go to bed and to wake up. Each night the times were adjusted to four hours later. This continued for three weeks. Because their body’s internal clocks were not able to adjust to the changing times, they started to set their own rhythms.
The researchers found that resting energy expenditure was lowest at the circadian phase that corresponds to the late biological night. Energy expenditure was highest at the biological afternoon into evening phase. In fact, the participants burned 10% more calories when at rest in the late afternoon and early evening than in the early morning hours.
Researchers from Brigham and Women’s Hospital and Harvard Medical School led the study. It was published on November 8, 2018, in Current Biology.