New research suggests diners order more food and drink when their waiter is on the heavier side, compared with slimmer waiters.
The study comes from researchers at the Cornell Food and Brand Lab in Ithaca, NY, an arm of Cornell University that regularly looks into the subtle intersection of food consumption and psychology.
Led by researcher Tim Doering, the study is published in the journal Environment and Behavior.
"No one goes to a restaurant to start a diet," he says. "As a result, we are tremendously susceptible to cues that give us a license to order and eat what we want. A fun, happy, heavy waiter might lead a diner to say 'What the heck' and to cut loose a little."
But "cutting loose" can be more detrimental than simply breaking a New Year's resolution to eat better.
With more than one third of adults in the US classified as obese - or 78.6 million individuals - obesity represents a major public health issue and drives some of the leading causes of preventable death, including heart disease, stroke, type 2 diabetes and certain types of cancer.
Diners with heavier waiters four times more likely to order dessert
To further investigate how external forces influence how much we order while dining out, the researchers observed the interactions between 497 diners and their servers in 60 different restaurants, including establishments such as Applebee's and TGI-Friday's.
Next, the team assessed what the diners ordered, the body mass index (BMI) of their servers and the size of the diners themselves.
Results showed that diners ordered significantly more when their waiters had higher BMIs, compared with wait staff with lower BMIs. In detail, diners with heavier waiters were four times more likely to order desserts and ordered 17.65% more alcoholic drinks.
Interestingly, Doering says that heavier servers had "an even bigger influence on the skinniest diners."
The researchers note that previous studies have shown that the lighting, music and where a diner sits can subconsciously bias what he or she orders.
Commenting on their study, coauthor Brian Wansink, PhD, director of the Cornell Food and Brand Lab, says:
"Deciding that you'll have either an appetizer or a dessert - but not both - before you get to the restaurant could be one of your best diet defenses."
Subtle influences on portion size
A previous study from the Food and Brand Lab, published in the Journal of Consumer Research in 2012, investigated how the color of our plates affects how much we eat.
The researchers of that study focused on an optical illusion known as the Delboeuf Illusion, named for the Belgian scientist who discovered it in 1865. The gist of the illusion is that, when looking at concentric circles, the perceived size of the interior circle alters when the circumference of the outer circle changes.
For example, as the outer circle becomes larger, the inner circle appears to become smaller.
This illusion relates to portion size and plate color in a similar way. The researchers found that study participants who had low contrast between their food and their plates (for example, pasta with Alfredo sauce on a white plate or pasta with tomato sauce on a red plate) served themselves 22% more pasta than those with high contrast between their food and their plates.
The team concluded their study by noting that if your goal is to eat less, you should choose plates that have high contrast with what you plan to eat. Or, if your goal is to eat more vegetables, they recommended pairing greens with a green plate.
The Cornell Food and Brand Lab are sure to produce further studies in future that reveal the subtle ways in which we are influenced to choose - or not choose - certain foods.
Commenting on their latest study, Wansink and Doering conclude:
"These findings provide valuable evidence in recent lawsuits against weight discrimination, and it suggests to consumers to decide what they will and will not order at a restaurant - such as a salad appetizer, no dessert and one drink - than to decide when the waiter arrives."
Earlier today, Medical News Today reported on a study that suggested processed foods raise the risk of autoimmune diseases.