Not only do evil fast food companies make us fat and tempt our children with deceptive advertising, they also make us impatient, according to a new study in Psychological Science.

In fact, mere exposure to fast food and related symbols can make us impatient, increasing preference for time saving products, and reducing willingness to save, the study found.

"Fast food is one of many technologies that allow us to save time," says University of Toronto researcher Sanford DeVoe, "But the ironic thing is that by constantly reminding us of time efficiency, these technologies can lead us to feel much more impatience. A fast food culture that extols saving time doesn't just change the way we eat but it can also fundamentally alter the way they experience our time. For example, leisure activities that are supposed to be relaxing can come to be experienced through the color glasses of impatience."

In one experiment, the researchers flashed fast food symbols, such as the golden arch of McDonald's, on a computer screen for a few milliseconds, so quick that participants couldn't consciously identify what they saw.

They found that this unconscious exposure increased participants' reading speed in a subsequent task compared to those in a control condition, even when there was no advantage to finishing sooner. In another study, participants who recalled a time when they eat at a food restaurant subsequently preferred time-saving products—such as two-in-one shampoo—over regular products.

A final experiment found people exposed to fast food logos exhibited greater reluctance for saving —choose a smaller immediate payment rather than opting for a much larger delayed payment.

The researchers admit that they have no idea whether there is a causal link between exposure to fast food, its related symbols and impatience. But that really doesn't matter because they know that exposure to fast food reinforces our emphasis on impatience and instant gratification.

Given the role that financial impatience played in the current economic crisis," says Chen-Bo Zhong, "we need to move beyond counting calories when we examine the consequences of fast food as it is also influencing our everyday psychology and behavior in a wider set of domains than has been previously thought."

Citation: Chen-Bo Zhong, Sanford E. DeVoe, 'You Are How You Eat: Fast Food and Impatience', Psychological Science (In Press)