Researchers have found that the sense of smell and behavior motivation play a role in determining why some people find it easier to stop eating when full while others struggle with this. They discovered a structural connection between two brain regions involved in regulating feeding behavior, using neurological imaging from the Human Connectome Project. The olfactory tubercle, associated with the sense of smell, and the periaqueductal gray, involved in motivated behavior responding to negative feelings, showed weaker connections in individuals with a higher body mass index (BMI). The researchers found that the smell of food is more appealing when a person is hungry, but becomes less attractive when they are full.
The researchers hypothesized that healthy brain networks connecting reward areas with behavior areas can regulate eating behavior by signaling when it is time to stop eating. People with disrupted or weak connection circuits may not receive these signals, leading to overeating even when not hungry. The study suggested that understanding these basic processes in the brain could be essential for developing treatments for overeating. The researchers believe that the structural connection between the olfactory tubercle and the periaqueductal gray may be linked to a person’s BMI and that future studies are needed to further explore the mechanisms in the brain regulating eating behavior.
Experts in the field, such as registered dietitian Emily Spurlock, who specializes in gut health and weight management, emphasize that the study offers scientific evidence supporting the idea that individuals eat for reasons other than hunger. Spurlock noted that some people may be more susceptible to overeating due to the influence of food smells and visual cues, which can override feelings of fullness. She highlighted the importance of being in tune with the body’s fullness signals and suggested that frequent overeating can desensitize individuals to these cues over time. Spurlock also raised the question of whether individuals can rebuild or strengthen the brain connections that regulate feelings of fullness to prevent overeating.
Therapist Kate Ringwood, who specializes in eating disorders, provided a different perspective on the study findings. She suggested that restrictive eating behaviors, whether mental or physical, can lead to a disconnect from the body’s hunger and fullness cues. Ringwood explained that when individuals restrict food intake, the body may enter a ‘survival mode,’ causing intense cravings and overeating when food is reintroduced. This cycle of restriction and overeating can create a sense of discomfort and disrupt the body’s natural signaling mechanisms related to hunger and fullness. Ringwood emphasized the importance of listening to the body’s cues and avoiding restrictive eating patterns to maintain a healthy relationship with food.
Overall, the study sheds light on the intricate connection between the sense of smell, brain circuits, and eating behaviors, providing insights into why some individuals may struggle with overeating. By examining the structural connections in the brain that regulate feelings of fullness and reward associated with food, researchers aim to develop strategies to help individuals better manage their eating habits. The findings underscore the importance of understanding the complex interplay between sensory perceptions, brain function, and behavior in shaping our relationship with food and managing our body weight effectively. Further research is needed to explore the underlying mechanisms and potential interventions to address overeating and obesity.
