Why can’t some children resist temptation? Why can’t most of them understand that it’s better to have a larger reward later than a smaller reward now? Why is it that, for some kids, whatever goes in the eyes (like a TV commercial for junk food) also goes into the mouth? Appetitive traits arise from both genetic and environmental influences. A National Institutes of Health report on appetitive traits in children says:
In this paper we describe the results of new studies using behavioural tests and psychometric questionnaires in large samples to show that individual variation in these appetitive traits relates to body weight throughout the distribution. We also describe twin studies and genetic association studies supporting a strong genetic component to appetite.
It might be useful to have a notion of what psychologists and social scientists mean by “built environment” and “social environment,” which are often set in opposition to each other, although closer examination reveals a fuzzy borderline. Dr. Mia A. Papas, of the University of Maryland School of Medicine, is a pediatrician concerned with the many ways in which diet, exercise, and the environment interact. She says:
The built environment encompasses a range of physical and social elements that make up the structure of a community and may influence obesity…. [T]he environment can be thought of as “all that is external to the individual,” with the term “built environment” encompassing aspects of a person’s surroundings which are human-made or modified, as compared with naturally occurring aspects of the environment.
But wait, isn’t the built environment assumed to be a separate phenomenon, in contrast to the social environment? Yet here is a scientist saying that social elements are part of the built environment, and the real contrasting element is the natural world of soil, plants, rocks, and weather.
Dr. Papas goes on to enumerate ways in which the built environment impacts human health. What happens when we always walk on cement and never on grass? What about those thousands of chemicals we absorb every day? The built environment also encompasses more tangible things, such as “housing, urban development, land use, transportation, industry, and agriculture.” The “food desert” concept, for instance, comes under the heading of the built environment.
Dr. Papas led a meta-study whose team first scoured through hundreds of scientific abstracts to find articles about suitable studies whose data, taken together, would clarify some points. They ended up with 20 applicable studies, but only three concerned children. (The great majority chose subjects from among adolescents and/or adults.) From this scant evidence they formed a not very surprising conclusion: Younger children are more influenced by their immediate environment, and teens are more influenced by the larger built environment.
Where it gets complicated
Often, the built environment can’t be changed. In other cases, it can be changed at great trouble and expense, including participation from the social environment in the form of, for instance, protest groups who have their own reasons for not wanting the built environment altered in that particular way. Before exerting influence to change some part of the built environment, it’s important to understand why it matters, and to hold a reasonable degree of certainty that the change will actually have some impact on childhood obesity.
Researchers look, for instance, at children’s proximity to fast food joints and/or health food retailers. They ask how the kids get to and from school. They also look at the proximity of parks and open spaces where kids can engage in physical activity. Dr. Papas’s team found that kids in poor neighborhoods live closer to playgrounds, which should be something to cheer about. It certainly sounds good on paper.
But therein lies the trouble with a lot of studies. The factors they try to measure, and the problems that arise when the researchers have to line up data from studies conducted by various individuals from different institutions at different times, and fit it together somehow — it gets kind of crazy. We can count the number of playgrounds in a neighborhood, but what if no children play there, because the park is a hangout for gang members? The measurement becomes meaningless. This is the sort of conundrum that can make these studies so frustratingly uninformative.
Your responses and feedback are welcome!
Source: “Appetitive traits in children. New evidence for associations with weight and a common, obesity-associated genetic variant,” NIH.gov, 07/25/09
Source: “The Built Environment and Obesity,” OxfordJournals.org, 05/28/07
Images by theimpulsivebuy