Nov. 17, 2015

For men, eating to excess might be eating to impress

Men have a reputation of doing just about anything to show off in front of women, no matter how seemingly absurd. That effort to impress apparently extends to their eating habits: A new Cornell study shows men eat significantly more food when in the company of women, a finding, researchers suggest, that has to do with a hardwired male urge to demonstrate prowess to the opposite sex.

For the study, Cornell researchers from the Food and Brand Lab observed adults lunching at an all-you-can-eat Italian buffet. They found men who dined with at least one woman ate 93 percent more pizza compared with those who ate exclusively with other men. That tendency to overeat extended to healthier options as well: Men ate 86 percent more salad in the company of women.

An explanation of the findings can be traced to an evolved tendency to show off to the opposite sex, according to Kevin Kniffin, visiting assistant professor at the Charles H. Dyson School of Applied Economics and Management and lead author of the study. Brian Wansink, professor and director of the Food and Brand Lab, and Ozge Sigirci, a former visiting scholar at the lab, are also authors of the study published Nov. 10 in the journal Evolutionary Psychological Science.

“The findings suggest that men tend to overeat to show off,” Kniffin said. “Instead of a feat of strength, it’s a feat of eating.”

By overconsuming food men unconsciously may be signaling their biological fitness, a paradoxical tactic in this case given that “overeating consistently is going to produce a body shape research shows tends to be viewed as unattractive,” Kniffin explained.

Kniffin said the findings fit with other examples of self-handicap behavior, where in this case men are showing off their fitness through excessive eating. Engaging in risky or unhealthy behavior, the thinking goes, demonstrates an extraordinary ability to tolerate challenges, even self-inflicted ones.

Previous studies have looked into the evolutionary mechanisms that influence female eating patterns, but disordered eating among men – such as the overeating found at competitive eating contests, which are typically dominated by male competitors – has not been closely scrutinized.

While the Cornell study suggests that men are the ones who overeat, it’s the women who report a sense that they are the ones who overdid it. Specifically, women eating with men reported feeling rushed during the meal and perceived that they overate despite researchers finding no evidence that they did so.

Regardless of the gender of the person, Kniffin said a lesson to take away from the study is the same: “The findings are clear that people should calm down when eating with members of the opposite sex. Men seem to be eating more, and women feel like they overate.”

Matt Hayes is managing editor and social media officer for the College of Agriculture and Life Sciences.