Blood sugar slumps affect how lean men treat the more rotund

Corpulent people often experience so-called weight prejudice because of their greater body mass. In the working world, this bias towards the more rotund plays out in the fact that they are less likely to be hired, are more often unemployed and are sometimes even paid less for the same job than leaner employees.

Peters' team asked 20 lean and 20 corpulent men to play a set of economic games that have previously been widely used to gain insights into the factors that influence the economic decisions that people make. The three games were played with the participants being aware of the physical appearance of their opponents, and while their blood sugar levels were either normal or abnormally low. The ultimatum game analyses fairness. In it, one player is asked to divide a fixed amount of money with someone else, while the other has the option of accepting or rejecting the offer. In the trust game, cooperation and faith in another can lead to an increase in the monetary outcome for a player, but at the risk of losing an investment. With the risk game, participants have to choose between safe and dicey prospects.

Even when experiencing normal blood sugar levels, lean participants in the ultimatum game tended to make fewer fair proposals than the more corpulent ones. In the trust game, lean men who experienced low blood sugar levels placed more trust in others sporting the same physique as themselves.

The playing of these games showed how economic decision-making is affected by the body weight of both participants concerned. It also highlighted that such pronouncements are often made less fairly and more egotistically when leaner decision-makers are experiencing low blood sugar levels and therefore have a short energy supply to the brain.

"Blood glucose concentrations should be taken into consideration when analysing economic decision-making," says Peters. "When relating these results to the working environment, the weight bias in economic decision-making may be relevant for employment disparities."

"One might therefore speculate that a lean personnel manager could prefer a lean job applicant and could offer him a higher salary, but that a corpulent personnel manager would not make a difference regarding body shape, in either hiring or salary decisions," Peters says by way of explaining how these findings might be played out in real life.