Trying to Lose Weight? Look Around the Table, Not Just On It

November 10, 2009

Standing next to a chubby pal might make you feel better about yourself, but it also could make you eat more -- or less -- depending on how big your buddy happens to be and how unbridled that person is at the buffet table. In fact, the weight and habits of a stranger in line ahead of you at some fast food place could impact your lunch choices, too.

A team of researchers that included W. P. Carey marketing professor Andrea Morales has discovered that it isn't merely the amount of food your tablemate orders that may affect your own eating decisions. Your companion's dress or trouser size is likely to carry considerable weight, as well.

Follow the eater

Morales and her colleagues are not the first scholars to examine how social interactions impact eating choices. An unpublished study found that people upped their intake after being primed with pictures of the overweight. In 2007, researchers found that people were more likely to become obese when a close friend, sibling or spouse became obese.

In 2003, an investigation showed that people adjust their own eating habits to stay more closely in line with what appears to be the norm of a group. That is, those who usually pile food on their plates ate less and the small-portion crowd ate more when someone set the norm by starting out with either a hefty or skimpy serving.

During that 2003 study mentioned above, researchers used a confederate to serve as the "anchor" or reference point that others would follow. So did Morales and her team. "We had our study participants come into a lab to view a movie clip," she explains. "We told them they could have snacks to eat while watching the movie." What the study participants didn't know is that consumption of those snacks was the actual research focus. And, to set the tone of how many munchies to grab, the investigators used a paid actress who helped herself to treats in front of the actual study participants.

What's more, at different times and with different test subjects, the actress played both the light- and heavyweight parts. Morales and her colleagues used a fat-simulating prosthesis to make the 102-pound, size-zero actress appear to be a lumpy size 16.

"We used the prosthesis because it controls for other variables that could influence behavior," Morales explains. The actress' facial features, gestures and even clothing were the same, as the research team dressed her in identical outfits regardless of whether she was appearing in her size-16 disguise or size-zero actuality.

Regardless of her size, the actress would help herself to a serving of M&Ms or other candies, and study participants would be invited to do the same. Then, the actress and study participant she was teamed with for that experiment each went into a separate room, presumably to watch the movie clip closely. In the end, what received even closer attention was the amount of food study participants took and ate.

Size matters

Results from the study show that it's not whether you eat with heavy or thin people that influences your own portions. According to the University of British Columbia's Brent McFerran, one of the other investigators, what matters is the combination of the other person's serving size and waist size.

"If the person you're eating with chooses a large portion, you're more likely to eat more if that person is thin than if they're obese," McFerran explains. "Conversely, if that other person chooses a small portion, you're more likely to eat more if that person is obese."

Why does your dining partner's size matter? "When the skinny person takes more, we use that as license to take more ourselves," Morales notes. "But, when the skinny person takes a little, we unconsciously think to ourselves, 'I want to be like that person. She's taking a little. I better take a little, too.'"

However, the reverse is true when we're eating with a heavy person. "We don't want to be like that person," Morales continues. "We don't want to emulate their behavior. So, when they take a lot, we take a little. When they take a little, we feel like we can afford to take a little more."

Study results also indicate that such disassociation is unconscious, but adjusting serving size based on companion size takes a little brainpower. In a third study, the investigative team had half of the test subjects memorize a 10-digit number while the other half only had to keep track of two digits. The numbers simulated "cognitive load," or consumed brainpower that could interfere with the ability to pay attention to a dining buddy's gut and snack portions.

Along with the memorization, study participants read a document that asked them to imagine being in a long line in an ice cream shop. Then, they were asked to answer a series of questions that, among other things, told the researchers whether the study participants noticed if the person in front of them was extremely heavy, which was the case in half of the narratives, as well as what that person ordered. Another question asked participants to imagine what they would order themselves.

As predicted by the researchers, people with a heavy cognitive load -- those who had to memorize the 10-digit number -- were less likely to emulate or remember the order of the person in front of them. "Our studies show that you still notice if the other person is bigger or smaller, but you don't adjust your own portion size if you don't have the cognitive resources to do so," Morales says.

But, your own body image may also have an effect on how susceptible you are to another person's influence. In this study as well as the two experiments performed with the sometimes bulked-up actress, questions also measured a participant's appearance self-esteem. In all the experiments conducted by Morales et al., participants with low appearance self-esteem were more strongly affected by the other person's portion decisions.

Heavy implications

As Morales and her colleagues discovered, consumers generally veered from behavior that mimicked a person in an unappealing group, namely the heavy consumer. If the big girl took a small portion, others took bigger ones. If Ms. Size 16 took a large portion, the study participants' portions were smaller.

Such disassociation from an unattractive person or group could have implications for marketers, Morales points out. That is, "if you have an ad aimed at affecting behavior, the person you have in the ad will have an impact. People may want to disassociate from your spokesperson." As an example, Morales et al. point to the idea of running an anti-binge drinking ad on campus using a studious type or an ostensible nerd as the spokesperson. It could backfire, they maintain.

She adds that the disassociation urge is so strong, people unconsciously do the opposite of the heavy role model or companion, even if that person's behavior is something one might ordinarily choose to engage in. "A lot of people report that they eat more for dinner when they're watching 'The Biggest Loser,'" she jokes. "They're disassociating, telling themselves they don't need to diet like the show's contestants."

She adds: "From a consumer standpoint, if you know this is happening on some level, you can correct for it."

With that in mind, readers might want to remember a little bit of advice from researcher Gavan Fitzsimons, the scholar from Duke University who worked on the study. According to him, people in the know might worry about dining with a heavy companion, but there is more danger in eating with a thin friend who chows down voraciously. In response, you're more likely to order a lot of food, too, and you probably will not make any conscious portion adjustment. In short, the "riskiest" pal to eat with "is that skinny friend with the big appetite," he concludes.

Bottom Line:

  • Studies show that people often adjust their own eating habits in relation to the habits of their eating companions.
  • Research also indicates that people try to disassociate from unpopular groups, such as the obese, and may unconsciously steer clear of emulating people in those unpopular groups.
  • The combination of such influences as portion sizes taken by others and the size of those others affects choices on portion size.
  • People are more likely to eat a lot if a thin companion takes a lot first; they'll eat more than a heavy companion who takes a small portion; and they'll eat less than a large person who piles the food high onto his or her plate.