Obesity rates have increased dramatically over the past 40 years in developed countries, and many consumer researchers have attributed this in part to the way that certain food products are marketed. In a recent study, consumer psychology researchers investigated the question as to whether people with obesity were more receptive to a certain kind of food marketing, and whether this susceptibility would decrease or stay the same even after significant weight loss.
 
The results of the study showed that, based on participants’ estimates of the caloric content of a variety of food products, people with obesity are more likely to be convinced by marketing claims that position certain foods as healthy. However, following substantial weight loss, this responsiveness to marketing reduced in tandem.
 
During the study, researchers recruited participants into three groups: patients who lost a substantial amount of weight through medical intervention (through either a gastric bypass or another kind of weight loss surgery) both 3 and 12 months after surgery, people with obesity who were not undergoing bariatric surgery, and people who were not obese.
 
To measure their responsiveness to marketing, the researchers evaluated certain impacts of advertising known as “framing effects,” in reference to how branding, advertising, and labelling can frame foods, thus influencing consumers’ evaluations of those foods and purchasing decisions. In one test, participants were asked to estimate the calorie content of well-known snacks and drinks, such as apple juice and granola bars which are framed as healthy, as well as soft drinks and chocolate bars, which are not framed as healthy.
 
While everyone underestimated the calorie content of snacks that were frame as healthy, people with obesity made more drastic underestimations.
 
To further test the effect, researchers had participants hypothetically choose a portion of French fries from a fast food restaurant, and gave them the nutritional information they would need to make an informed decision. The three options were always the same quantity – 71g, 117g, and 154g – but they were respectively labeled either small, medium, and large, or mini, small, and medium. This marketing tactic is used to make larger portions seem more reasonable.
 
“We measured how likely people were sensitive to that framing, and whether it would change their choice of fries quantity depending on how the portions were labeled,” Dr. Yann Cornil, lead author of the study, said. People with obesity were more likely to follow the labeling, and not the actual information about quantity, and so would choose the portion labeled ‘medium’ in the latter set even though it matched the large portion from the first set.
 
Based on the results of the post-bariatric surgery group, the researchers concluded that when obese people lose a significant amount of weight through bariatric surgery, their level of responsiveness to food marketing drops substantially.
 
“And after 12 months, their responsiveness to food marketing reaches the level of people with more medically-recommended weight,” Cornil said. It’s not clear, however, whether the changes in responsiveness were triggered by physiological changes (hormonally-based neurological shifts or gut microbiota changes) or the desire to adopt healthier lifestyles and habits.
 
“The results clearly suggest a bidirectional influence between people’s weight status, psychology, and responsiveness to the environment – including marketing,” Cornil said. “So, it’s a complex relationship.”
 
The results seemed to rule out a deeper-rooted psychological disposition, Cornil said. Had the researchers observed a continuously high responsiveness to food marketing after weight loss, “that would mean people are endowed with unchangeable psychological characteristics that would always make them more responsive to marketing – which would make it very difficult to sustain a medically-recommended weight. But one of the positive things is that after significant weight loss, people become less responsive to marketing, such that it is more sustainable to remain at a lower body mass index.”
 
Cornil added that the findings are especially important due to ongoing debates over whether marketing messages, especially for foods high in calories and low in nutrition, are at least partly responsible for the obesity epidemic, with a struggle to achieve empirical evidence.
 
“Our results provide important insights for policy-makers in charge of regulating food marketing to curb obesity,” he said.