There's a new study that suggests there's a link between the amount that people eat at restaurants and their server's body mass index. The two researchers behind it, one of whom is Brian Wansink, head of Cornell's respected Food and Brand Lab, observed about 500 diner-server interactions in 60 restaurants and reported that customers ordered more food "regardless of their own body type" if the waiter was heavier-set (i.e., for the purposes of this study, they had a BMI of 25 or higher).
What customers indulged in wasn't exactly the healthiest stuff on the menu, either: "Specifically," writes the duo, "they were four times as likely to order desserts ... and they ordered 17.65% more alcoholic drinks." Customers did this even when the other factors were accounted for, like ethnicity, gender, height, and age.
Wansink guesses that diners may be subconsciously justifying (or perhaps wrongly blaming the server for) eating and drinking more than usual in these kinds of circumstances, because a "heavy person sets a social norm." People basically reason Eh, why not?, in other words, because humans like to fit in. As goofy a mental image as this creates, the authors' conclusion is to map out in advance how much to order, "such as a salad appetizer, no dessert, and one drink," rather than deciding "when the waiter arrives."