Is it genetic that children eat a lot when watching commercials?

Children exposed to food advertising are more likely to overeat, especially if they carry a particular version of a gene linked to obesity.

Children with a version of the gene that interacts with junk food ads are more likely to snack even when they are full, putting them at higher risk of obesity. The fat mass and obesity gene, also known as the FTO gene (which comes in several slightly different versions), is the first gene to be linked to obesity by genetic studies, according to the International Journal of Obesity in October.

Previous research has shown that food advertising on television can influence how people respond to and consume food. Previous research has also shown that carrying the FTO gene is associated with a 20% higher risk of obesity than others.

In the study, 172 children (9-10 years old) at Children's Hospital at Dartmouth-Hitchcock were tested for the gene, with results showing that 16% of the children carried the most dangerous version, 18% carried the version associated with the lowest risk of obesity, and 48% carried the moderate-risk version.

In the entire group, 26% of the children were obese, and most had the high-risk genotype.

In the experiment, all children were served lunch and then randomly assigned to watch a 34-minute children's television show that differed only in the advertisements for food or toys, with marshmallows, cookies, chocolate, and cheese sticks to eat while watching. The researchers then measured the number of calories the children consumed, as well as surveyed them about their hunger.

Children who watched the food commercials (which included marshmallows) ate an average of 48 more calories of marshmallows than children who watched the toy commercials. However, children with the high-risk FTO gene who watched the food commercials ate 125 more calories than average. Children with the intermediate-risk version of the FTO gene ate 59 more calories, and children with the low-risk FTO gene ate 3 fewer calories than average.

The U.S. food industry spends $1.79 billion a year marketing food to children under 11, according to the Federal Trade Commission. Cable TV viewers see an average of 15 food commercials on TV every day, or 5,500 ads a year.

According to Dantri