A collection of 11 papers by US researchers published online on Tuesday suggests that the reason American childhood obesity is so high and increasing is because children and their families find it very difficult to make appropriate choices about food and diet given the mostly unhealthy range of options and messages they are exposed to, and school policies that are increasingly limiting the range and amount of physical activity don’t help.

The research forms part of a large collaboration supported by the Robert Wood Johnson Foundation called Bridging the Gap (BTG). The papers are published in the American Journal of Preventive Medicine.

Co-author of many of the studies, is Dr Frank Chaloupka, an economics professor at the Department of Economics and Institute for Health Research and Policy, in the University of Illinois at Chicago. He said that:

“We have in our schools and communities a perfect storm that will continue to feed the childhood obesity epidemic until we adopt policies that improve the health of our communities and our kids.”

BTG collects data from the Monitoring the Future (MTF) surveys of 8th, 10th, and 12th grade students. These include surveys of MTF school administrators about school food environment and physical education; information about the communities in which the MTF schools are situated; reviews of state policies; and collection of relevant data from public and commercial archives. The information is analyzed in lots of different ways, individually according to source and in combination.

BTG was set up ten years ago to look into the impact of policies, programmes, and environmental factors on adolescent consumption of alcohol, tobacco and illegal drugs and their effects.

The project involved scientists from many fields across a range of nationwide academic research centres.

They studied different leves of social organization, from schools, through communities, to states.

Given the rise in more recent years of childhood and adolescent obesity levels, the BTG expanded its focus to include the impact of policies, programmes, environment and other factors such as physical inactivity and diet on this growing problem.

Dr Lisa Powell, also of the University of Illinois at Chicago and author of a paper that examined the impact of tv advertising, restaurants, supermarkets and convenience stores in the communities the adolescents spend their daily lives in said that:

“The environment that they live in matters. The general environment around them is not really conducive to a healthy lifestyle.”

When people have to rely on convenience stores because they cannot travel to the supermarkets, families tend to eat less healthy food.

And teens at home are faced with a torrent of advertising that encourages them to eat unhealthy food found Powell and colleagues who studied over 200,000 tv ads aimed at teenagers between 2003 and 2004 on some of the best rated shows. Over 25 per cent of them were for fast food, sweets and drinks.

They found that overall fast food ads take up 23 per cent of all food ads that teenagers are exposed to.

A high percentage of fast food restaurants occur in low income communities, found the researchers, with the highest of them all occurring in black urban communities.

Another paper by researchers from the University of Michigan found that schools are no better with teenagers readily exposed and having access to sugary and high fat foods and beverages. Most of the schools they surveyed had contracts with soft drinks providers.

BTG’s early research on the link between adolescents’ diet, physical activity and obesity, much of which is reported in the 11 papers, shows that environment plays a strong part. It also explains much of the observed disparities in racial, ethnic and socioeconomic status.

The editorial that comprises the first paper concludes that:

“The growing recognition of the public health and economic consequences of childhood, adolescent, and adult obesity has led to a variety of policies, programs, and other interventions to stimulate healthy eating and physical activity, often despite the lack of evidence on their impact.”

“BTG and others are working to build the evidence base for effective interventions to address this significant problem, but much remains to be learned.”

The 11 Bridging the Gap Papers can be found in:
American Journal of Preventive Medicin, Volume 33, Issue 4, Supplement 1, October 2007.

Click here for contents list of this issue with links to Abstracts of all articles.

Written by: Catharine Paddock