VANCOUVER -- New research out of a B.C. university found that people with obesity were more responsive to food marketing, but that responsiveness dropped when they lost a significant amount of weight. The study, conducted at the University of British Columbia, suggests the findings are important because researchers assumed for years that food marketing is responsible to high rates of obesity in developed countries. Dr. Yann Cornil, lead researcher on the study, told CTV News Vancouver there doesn't appear to be any evidence of that. "People with obesity tend to be more responsive to marketing tricks, to marketing techniques and tend to underestimate calories more when a product is marketed as healthy," he said. "They tend to upsize their portions."