Childhood obesity is a critical public health problem in the U.S. In order to become overweight, children must repeatedly consume calories in excess of those required for growth and daily functioning. Consumption of excess calories is not necessarily driven by feelings of hunger. For example, most children will consume highly palatable food when it is presented to them immediately after they have eaten to satiation. The extent of this behavior, eating in the absence of hunger (EAH), has been strongly associated with overweight and weight gain in children;however, little is known about the genetic and environmental factors that affect this behavior. In this experimental study, we will recruit 200 children who are 9-10 years old from the general population to participate in an EAH study. All children will first be fed a standardized meal that provides 50% of their estimated daily calorie requirements for their age, gender, height, weight, and activity level. After consuming the meal ad libitum, the child will be randomized to view a 20 minute cartoon that has eight embedded 30- second child-directed advertisements for food (experimental condition) or toys (control condition), as well as four neutral advertisements. After watching the cartoon, the child will be taken to a room with highly-palatable foods and toys for 10 minutes. The main outcome will be the amount of food consumed during the 10-minute snacking period and the main exposures will be the child's genotype for the fat mass and obesity associated (FTO) gene rs9939609 allele as well as the exposure to food vs. toy advertisements. We hypothesize that children with at least one copy of the FTO rs9939609 A allele will consume more calories during the snacking period than those who are homozygous for the T allele. We also hypothesize that children with the high risk FTO allele be more affected by television food advertisement exposure than children who do not;i.e. the relative difference in calorie consumption in the food vs. toy advertisement conditions will be greater in children with an AA or AT genotype compared to those with a TT genotype. In a subset of 20 participants, we will also utilize functional Magnetic Resonance Imaging (fMRI) in order to better understand how food advertisements affect children. This preliminary study will inform a future, better-powered study on genetic factors that influence the neural response to food advertisements and the association between this neural response and child EAH. If successful, this study will help to determine whether some children are genetically predisposed for EAH, a trait associated with adiposity in children. It will further elucidate whether some children are particularly vulnerable to unhealthy eating behaviors after viewing television food advertisements. The results of our study can inform child obesity intervention and prevention programs as well as public policy regarding television food advertisements during child programming.
This research studies how children's fat mass and obesity (FTO) associated genotype and television food advertisement exposure relates to eating when having already eaten to satiety. We will additionally use brain- imaging techniques to study how television food advertisements influence children. This research is critical to guiding child obesity intervention and prevention programs as well as policy on child-directed food advertisements.
|Gilbert-Diamond, Diane; Li, Zhigang; Adachi-Mejia, Anna M et al. (2014) Association of a television in the bedroom with increased adiposity gain in a nationally representative sample of children and adolescents. JAMA Pediatr 168:427-34|