New research published in PLOS ONE has shown that stress impacts the brain’s responses to food cues in both individuals with obesity and individuals without obesity.
The study involved 29 participants who completed experiments using functional magnetic resonance imaging (fMRI). Seventeen of the participants had obesity, while the other 12 participants were considered lean. Each participant completed two fMRI scans, with one of the scans coming just after a social and physiological stress test. During the scans, participants completed a “food word reactivity test” in which they reacted to a list of foods and told the researchers how much they wanted each food and whether they felt that they should or should not eat that food. The goal of the study was to determine whether stress and/or obesity impact the brain and whether they change appetite or food control.
The study showed that stress does impact how the brain responds to food cues. In participants with obesity, the scans showed greater activation of the brain in a reward region after they took the stress test. Similarly, lean individuals who reported higher subjective stress after the stress test showed lower brain activation in a region related to cognitive control. Lean individuals and individuals with obesity also showed some differences in brain responses; individuals with obesity showed less activation of regions associated with cognitive control than lean individuals, and the effect was particularly strong for high-calorie foods.
Obesity is rising in America and around the world, and obesity has strong links to a variety of health problems, including cardiovascular disease. The results of this study suggest that lowering stress levels may be an important method for controlling obesity.