Brain Mechanisms of Overeating in Children
Reducing intake from large portions is of critical importance to preventing obesity. People consistently eat more when they are served larger portions, a phenomenon known as the portion size effect. The mechanisms of the portion size effect are not well understood, and investigating the underlying neurobiology that drives this phenomenon may inform the development of more effective obesity prevention programs. The proposed research will follow healthy weight children who vary by family risk for obesity to identify the neurobiological and appetitive traits that are implicated in overeating and weight gain during the critical pre-adolescent period. We expect results to confirm the hypothesis that reduced function of brain inhibitory pathways and increased activity in brain reward pathways in response to portion size cues contributes to excess intake with large portions and greater weight gain over time, particularly in children who have higher risk for obesity. The proposed studies will characterize the relationship between brain response to portion size and eating behavior and will allow us to determine whether brain and behavioral responses predict body fat gain during pre-adolescence. These studies will contribute essential information to our understanding of the pathways implicated in overeating and obesity and will facilitate the characterization of “at risk” phenotypes that can be targeted by prevention programs.
There will be seven in person visits with two DEXA measurements, one fMRI scan and five meals.
The child must not have any food allergies to foods used in the study, learning disabilities, psychological diagnoses, red/green color blindness, or claustrophobia.
The child must not be taking any medications known to influence cognitive function, taste, appetite or blood flow
The child's BMI must be below the 90th percentile at the first visit
The biological mother and father must have a BMI between 18.5-25 kg/m2 (low-risk group) or greater than or equal to 30 kg/m2 for mothers and greater than or equal to 25 kg/m2 for fathers (high-risk group) and 1 parent must attend all visits.
Children will be excluded if they have any food allergies, learning disabilities, psychological diagnoses, red/green color blindness, or claustrophobia
Children will be excluded if they are taking cold or allergy medication, or other medications known to influence cognitive function, taste, appetite, or blood flow
Children will be excluded if their BMI is above the 90th percentile at the first visit
Families will be excluded if the biological mother or father do not fit the BMI requirements