People with obesity, compared to those without obesity, are more responsive to marketing framing, but this responsiveness decreases after weight loss surgery. Additionally, people with obesity exhibit less hedonic discrimination across sweet and fatty tastes, but this indifference decreases after weight loss surgery.

“Past studies have shown that gastric banding and gastric bypass reduce the size of the stomach, making people feel fuller quickly, so they feel less hungry and tend to eat less. In our research, we aim to also understand how weight loss surgery impacts consumer psychology” said Yann Cornil, Associate Professor of Marketing & Behavioral Sciences at the University of British Columbia, during Sasin Research Seminar.

According to his research on “Obesity, Responsiveness to Food Marketing, and Taste Perception Before and After Bariatric Surgery,” obese individuals become less influenced by marketing after surgery because they develop internal preferences and better understand their likes and dislikes, reducing their reliance on external marketing cues. The surgery also reduces impulsivity due to biological changes in gut hormones and microbiota. Since the 1970s, the prevalence of obesity has increased dramatically all over the world, mainly due to the proliferation of hyperpalatable foods in large portions. Humans evolved in an environment where high-calorie foods were scarce and hunting for food was necessary. With food now readily available everywhere, exerting self-control has become increasingly challenging. In a decade-long study, Dr. Cornil examined more than 70 patients with severe obesity (BMI over 40) before surgery, three months after surgery, and twelve months after surgery. He found that marketing tactics, such as portion size labeling, influence food choices to a greater extend before surgery than 12 months after surgery. Dr. Cornil’s research indicates that pre-surgery, obese individuals are swayed by portion labels, while post-surgery, they show less influence. One marketing scheme contributing to obesity is the misleading labeling of portion sizes. Dr. Cornil showed a table comparing French fries from different brands, explaining that “small” fries are actually medium portions, and “medium” fries are extra-large. People tend to choose the “medium” option, not realizing it is a large portion. Bariatric surgery alters individuals’ reliance on marketing cues, affecting their preferences and reducing impulsiveness when choosing food. This shift highlights the complex interplay between biology, behavior, and marketing in obesity dynamics. Before surgery, people with obesity are more influenced by size labels; after surgery, they are less influenced. Dr. Cornil also conducted research on sugar and fat preferences using different types of yogurt, from unsweetened to high-sugar, as well as low-fat and high-fat varieties. Before surgery, people with obesity were rather indifferent across the different varieties, that is, they did not exhibit strong preferences. After surgery, they developed internal preferences, preferring specific combinations of sugar and fat. Dr. Cornil’s findings emphasize the critical role of bariatric surgery in modifying eating behaviors and preferences, offering valuable insights for addressing the obesity epidemic in a world where high-calorie foods are omnipresent, and marketing strategies often exacerbate unhealthy eating habits.