Sitting around doing nothing doesn't burn many calories. Sitting around working on a computer doesn't either. But we apparently eat as if it does.
Researchers at Universite Laval in Canada gave three 45-minute tasks to 14 women. The first task: to relax in a sitting position. The second task: to read a document and write a summary of it. The third task: to complete a variety of memory and attention tests on the computer.
Then the participants were invited to pig out at a buffet.
The researchers had already established that the mental work required only three more calories than simply sitting. But the women ate 203 more calories after the reading-writing task -- and 253 more calories after the memory and attention task -- than they did after hanging out. One doesn't need to compute the day's number of hours at the computer to know this doesn't bode well for the waistline.
The mental tasks were linked to greater fluctuations in glucose and insulin levels, pointed out the researchers, who also took blood samples of the women during the study. (No free buffet and all that...)
"Caloric overcompensation following intellectual work, combined with the fact that we are less physically active when doing intellectual tasks, could contribute to the obesity epidemic currently observed in industrialized countries," the study's main author, Jean-Philippe Chaput, said in a news release.
It's unlikely he's suggesting we should be lazier. But take from this what you will.
The study was published online recently in the journal Psychosomatic Medicine.
-- Tami Dennis
Photo credit: Fabrice Coffrini / AFT / Getty Images