13 September 2008

Wanted: Glucose

I spend a lot of my days with my stomach growling...which is both unusual and also a bit puzzling. Let's face it, it's not like I'm doing hard labour or undertaking feats of athletic greatness. I'm usually sitting at my desk fussing over spreadsheets, attempting to stem the tide of e-mail, or in some sort of meeting. These are not major calorie-burning activities. I assure you that little or no sweating is involved. And then, I saw this article from Science Daily:
A Université Laval research team has demonstrated that intellectual work induces a substantial increase in calorie intake. The details of this discovery, which could go some way to explaining the current obesity epidemic, are published in the most recent issue of Psychosomatic Medicine.

The research team, supervised by Dr. Angelo Tremblay, measured the spontaneous food intake of 14 students after each of three tasks: relaxing in a sitting position, reading and summarizing a text, and completing a series of memory, attention, and vigilance tests on the computer. After 45 minutes at each activity, participants were invited to eat as much as they wanted from a buffet.

The researchers had already shown that each session of intellectual work requires only three calories more than the rest period. However, despite the low energy cost of mental work, the students spontaneously consumed 203 more calories after summarizing a text and 253 more calories after the computer tests. This represents a 23.6% and 29.4 % increase, respectively, compared with the rest period.

Blood samples taken before, during, and after each session revealed that intellectual work causes much bigger fluctuations in glucose and insulin levels than rest periods. "These fluctuations may be caused by the stress of intellectual work, or also reflect a biological adaptation during glucose combustion," hypothesized Jean-Philippe Chaput, the study's main author. The body could be reacting to these fluctuations by spurring food intake in order to restore its glucose balance, the only fuel used by the brain.

"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," said Mr. Chaput. "This is a factor that should not be ignored, considering that more and more people hold jobs of an intellectual nature," the researcher concluded.

Okay, so maybe I'm not an intellectual; but there's no doubt my brain is on a steep learning curve with the new job. I am inundated with various novel things to absorb. My body may be doing very little, but my brain is in Energizer Bunny Mode...and in its quest for ready energy, it's making me think I'm hungry. So, I've been stocking up on some 100-calorie packs of food and some fruit to have at work with me. Hopefully some small bites during the day will keep my mind going and my stomach quiet.


Travis A. Wittwer said...

So that is why I am hungry all of the time :O)

Hugh O'Donnell said...

Ahhh, thank you, SG. Now I can rationalize the skipped days at the gym and let my wife know I had my daily exercise at the keyboard!

Just kidding. ;)

Still, it's good to know that brain work is totally wasted. :D