Toronto: A new Canadian study shows that thinking too much can lead to overeating and thus obesity.

In their study at Universite Laval in Quebec City, Canadian researchers found that the stress of intellectual work makes people eat more, thus raising their calorie intake and causing obesity.

As part of their study, the researchers asked 14 students to eat at a buffet after performing three easy but different tasks: Just sitting and relaxing; reading and summarizing a text, and doing memory tests on a computer.

The researchers said these three tasks consumed very little energy, with students doing mental work needing just three calories more than those relaxing.

But they found that the students ate 203 extra calories after reading and summarizing the text, and 253 more calories after doing the computer-based memory tests.

Their blood samples - taken before, during and after the three task sessions - also showed that their glucose and insulin levels shot up during mental work (computer memory tests).

Explaining this, study leader Jean-Philippe Chaput said that glucose serves as fuel for brain during any mental or intellectual work.

To meet this need and keep its glucose balance in check, the body might be consuming more food, thus more calories.

``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,'' he said.

Chaput warned that obesity could become rampant in the future as more and more people get involved in intellectual work around the world. IANS