Friday, 5 September 2008 by Dr Maytel
Food for thought: Intellectual activities make people eat more than when just resting, according to a study that sheds new light on brain food. Researchers split 14 university student volunteers into three groups for a 45-minute session of either relaxing in a sitting position, reading and summarizing a text, or completing a series of memory, attention, and vigilance tests on the computer.
The scientists had determined beforehand that the thinking sessions consumed only three calories more than resting. After the sessions, the participants were invited to eat as much as they pleased.
Though the study involved a very small number of participants, the results were stark.
The students who had done the computer tests downed 253 more calories, or 29.4 percent more than the couch potatoes. Those who had summarized a text consumed 203 more calories than the resting group.
Blood samples taken before, during, and after revealed that intellectual work causes much bigger fluctuations in glucose levels than rest periods, perhaps owing to the stress of thinking.