Brain Mechanisms of Overeating in Children

Overview

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. The investigator's central hypothesis is that increased intake from large portions of energy dense foods is due in part to reduced activity in brain regions implicated in inhibitory control and decision making, combined with increased activity in reward processing pathways. To test this hypothesis, the investigators will recruit 120 healthy weight children, aged 7-8 years, at two levels of obesity risk (i.e., 60 high-risk and 60 low-risk) based on parent weight status. This will result in 240 participants: 120 children and their parents.

In aim one, the investigators will use functional magnetic resonance imaging to characterize the brain regions which are activated in response to food portion size and compare these regions between high- and low-risk children. Second, the investigators will determine the relationship between brain response to visual portion size cues and measured food intake when portions are increased in the laboratory. Third, the investigators will determine the relationship between brain response to large portions and other validated measures of overeating, including satiety responsiveness and the amount of calories children consumed from high calorie snacks when they are not hungry (i.e., eating in the absence of hunger). Fourth, the investigators will conduct follow-up visits one year after baseline to determine the extent to which baseline brain and behavioral responses to portion size predict gains in adiposity assessed by anthropometrics (body weight, height, and dual-energy x-ray absorptiometry). Secondary study endpoints include the relationship between child behavioral and brain response to food portion size and physical activity assessed by accelerometry and questionnaires, inhibitory control assessed by a stop signal test, reward-related design making assessed by a computer task, working memory assessed by an N-back task loss of control eating, child sleep, child working memory, child meal microstructure assessed by observational meal coding, parent rated eating behaviors, and parental feeding practices.