BACKGROUND/OBJECTIVE: Exposure to food advertisements may cue overeating among children, especially among those genetically predisposed to respond to food cues. We aimed to assess how television food advertisements affect eating in the absence of hunger among children in a randomized trial. We hypothesized that the fat mass and obesity-associated gene (FTO) rs9939609 single-nucleotide polymorphism would modify the effect of food advertisements.
SUBJECTS/METHODS: In this randomized experiment, 200 children aged 9-10 years were served a standardized lunch and then shown a 34-min television show embedded with either food or toy advertisements. Children were provided with snack food to consume ad libitum while watching the show and we measured caloric intake. Children were genotyped for rs9939609 and analyses were conducted in the overall sample and stratified by genotype. A formal test for interaction of the food advertisement effect on consumption by rs9939609 was conducted.
RESULTS: About 172 unrelated participants were included in this analysis. Children consumed on average 453 (s.d.=185) kcals during lunch and 482 (s.d.=274) kcals during the experimental exposure. Children who viewed food advertisements consumed an average of 48 kcals (95% confidence interval: 10, 85; P=0.01) more of a recently advertised food than those who viewed toy advertisements. There was a statistically significant interaction between genotype and food advertisement condition (P for interaction=0.02), where the difference in consumption of a recently advertised food related to food advertisement exposure increased linearly with each additional FTO risk allele, even after controlling for body mass index percentile.
CONCLUSIONS: Food advertisement exposure was associated with greater caloric consumption of a recently advertised food, and this effect was modified by an FTO genotype. Future research is needed to understand the neurological mechanism underlying these associations.
