CONTRARY to popular belief, exposure to fast food on the way to and from school does not systematically affect children's weight, according to a study conducted in the United States. These results run counter to the policies implemented in some major American cities to combat childhood obesity, one of the country's public health priorities.

Should fast-food restaurants around schools be eliminated? This is the question currently being asked by some cities, including Austin and New York, which are considering banning fast-food restaurants near schools to combat childhood obesity. Many health experts around the world have been concerned for years about the impact of fast food on the eating habits of younger children. While several studies have already shown a correlation between fast food and obesity, a new survey reports that the availability of fast food at these restaurants on the way to and from school has no influence on children's weight.

Researchers looked at children's exposure to fast food on their way to and from school and its impact on body mass index (BMI). In particular, they looked at changes in this exposure as children progress through the school system, from elementary school to middle school, or from middle school to high school. They used the BMI of students in Arkansas, collected between 2004 and 2010, as well as their home and school addresses.

In a second step, scientists identified fast-food establishments on the participants' route to school, including McDonald's, Burger King, Dairy Queen, take-out pizzerias, Taco Bell, Subway, Quiznos, KFC, and Chick-Fil-A. They then measured the impact of changes in this exposure as students progressed to higher education institutions.

No "significant relationship"

Published in the journal Q Open, the study first showed that more than two thirds of the sample (69.6%) had no exposure to fast food within 800 meters of their home, and that 45.2% had at least one fast food restaurant within 800 meters of their school. The researchers also explained that changes in exposure to fast food did not have an impact on participants' BMI.

If we look at the results in detail, we find that there is no impact between exposure to fast food and BMI in elementary school students. However, the researchers indicate a slight variation in BMI for high school students who have at least five fast-food outlets near their school and for high school students who have between two and four fast-food outlets on their route compared to those who do not. In their findings, however, the scientists indicate that exposure to fast food, by itself, is not a factor in excessive weight gain in children. However, they do not rule out the possibility that effects on BMI may be observed over a longer period of time.

Conflicting studies

Numerous studies have pointed a finger at the presence of fast-food restaurants near schools in the United States, prompting some cities to take steps to replace fast-food restaurants with healthier alternatives. In 2009, a study published by the National Bureau of Economic Research in the United States revealed that the presence of a junk food restaurant located within 150 meters of a school could increase obesity by 5%.

Further research may therefore be conducted to determine even more precisely the role of fast-food restaurants on the eating habits of younger people.