In a study called 'The Waiter's Weight: Does a Server's BMI Relate to How Much Food Diners Order?' by researchers Tim Döring and Brian Wansink, which was published in the Environment and Behavior journal, the diner-waiter relationship is explained in-depth. Besides music affecting dining behaviour - e.g. Ed Sheeran and Taylor Swift music in the background make certain food taste great while Justin Bieber music and similar tunes lessen the appeal of food - or lighting and the general ambience affecting the enjoyment of a meal, the body mass index (BMI) and weight of people involved in the meal apparently also play significant roles.
Döring and Eansink explain: "In a novel approach, we showed that diners can be influenced by their surroundings in general and furthermore by their social interactions in particular. This study suggests that it does not take profound interactions between individuals to alter their eating behavior."
The researchers recorded the BMI of both diners and waiters prior to observation. Out of 497 observed interactions between diners and waiters across 60 full-service restaurants, the team was able to determine a pattern in the how the diners ate - i.e. the type and amount of food and beverages that they ordered. Apparently, the higher the waiters' BMI the more 'encouraged' diners feel to order and consumer more food and drinks. This is regardless of their own BMI. Dessert is almost a given if the waiter is on the larger BMI range.
The Centers for Disease Control and Prevention qualifies that discounting those of athletes who have more muscles, a BMI between 25 and 29.9 indicate an overweight condition. In the study, a BMI of at least 25 categorised a participant on the heavy side. Restaurants therefore seem to have more to gain in terms of sales by hiring heavier servers.
The study explained this correlation by saying that heavy individuals in a way set the social norm, so that diners feel more comfortable about consuming more when in their company.
