Printable View: The Environmental Assessment

Eat less, exercise more. It sounds like a simple enough solution to prevent childhood obesity, but perhaps it is too simple. Some research suggests that we have such an obesity problem in the United States because we live in an obesogenic environment--one that encourages us to eat too much and exercise too little.¹

A key step in taking an overall ecological approach to obesity prevention is to assess what environmental factors are contributing to the problem. Environmental causes require environmental solutions. An environmental intervention modifies the environment to make healthy eating and active living choices easier to make. Put another way, an environmental approach makes healthy choices easier for whole communities.

The Approach

Traditionally, health professionals have focused on the individual and his or her behavior. However, an environment that facilitates healthy food and activity choices has the potential to prevent overweight in many members of a community, not just in a few individuals. While individual interventions may be useful to treat a person who is already obese, environmental interventions may be more effective in stopping the obesity epidemic.

Let's compare individual and environmental approaches to obesity prevention.

Comparison of Individual and Environmental Approaches to Obesity Prevention

An individual approach tries to change a person's behavior. An environmental approach focuses on changing an entire community through structural, social, economic, and/or policy change.

In an individual approach, the person him- or herself is responsible for change. Our efforts as health professionals reach only those who are interested in changing. In an environmental approach, community collaborations are needed for change, and their efforts reach the entire community.

To reach individuals, we take an educational or behavioral approach. In other words, we try to help people learn new information or behaviors. In contrast, an environmental approach is a community development approach, in which we try to help the community identify opportunities and resources for changing the eating and physical activity environment.

One risk of individual approaches is that they can stigmatize the people we work with. Perhaps even worse, they can contribute to blaming victims for behaviors that may be very difficult for them to change because of external, environmental factors. For example, it is impossible for a child to choose healthy foods if those foods are not available and affordable. Environmental approaches, on the other hand, can support individual approaches by making healthy food and activity choices more readily available. For example, providing balls and other sports equipment to school children in one study increased their physical activity at recess.²

The Evidence

As health professionals we have traditionally taken individual, behavioral approaches to obesity prevention. Because environmental interventions to prevent obesity are relatively new, scientific evidence for what works and what doesn't is still needed in many areas.

There is some evidence of environmental causes of obesity and for strategies that may be effective. For example:

• Higher rates of obesity have been associated with factors that may discourage walking, such as urban sprawl;³ living on a highway and/or having no sidewalks, paths or shops within walking distance;⁴ and questionable neighborhood safety.⁵ It has also been associated with neighborhood deprivation.⁶
• More people take the stairs if stairwells are more attractive and if they are aware of the difference in calories burned between taking the stairs and taking an escalator.⁷

An Environment for Exercise

Environmental interventions that promote physical activity and prevent obesity are beginning to emerge, and many more studies are underway. The Task Force on Community Preventive Services has recommended several evidence-based practices to increase physical activity⁸, including:

• Community-wide campaigns: for example, a program that distributes free pedometers and helps to organize walking clubs
• Point-of-decision prompts: for example, putting up signs next to elevators that advertise the number of calories burned by climbing stairs
• School-based physical education: for example, making comprehensive physical education a daily routine in schools
• Community places for physical activity: for example, making walking and biking paths, basketball courts, and parks available locally.

An Environment for Healthy Eating

Environmental approaches to obesity prevention through attention to community food choice settings are less well developed than those for encouraging physical activity. Some approaches that have been successful include:

• Price reductions on fruits and vegetables and healthier snack foods¹⁰
• Consumption of fruits and vegetables, which has been found to increase with the number of supermarkets in an area¹¹
• School-based strategies for getting students to buy and consume healthful beverages, like competitive food policies, changing food and beverage contracts, social marketing of healthful foods, and changing policies for food involved in fund raising.¹²

Environmental Intervention Dimensions

Dimensions of Environmental Interventions to Prevent Obesity¹³

Environmental interventions to prevent obesity fall into two main categories: Those that promote healthy food choices and those that promote active living.

Within these two categories, environmental interventions can be targeted to any of four environmental domains:

• The structural, or built environment. This is the infrastructure of housing, workplaces and public facilities such as schools, transport systems, sports grounds, sidewalks, and parks.
• The social environment. This includes community norms, social networks and support, and crime levels. Social interventions can occur through parent-teacher organizations, conventions about what foods kids bring to school for classroom parties, and community crime watches.
• The economic environment. This includes employment and education levels, income and income inequality, and cost of living. For example, the fact that schools with tight budgets often find it difficult to give up revenues from soft drink sales is clearly a feature of the economic landscape.
• The policy environment. This includes health and public school policies as well as laws. School policies about foods in vending machines and USDA guidelines for school lunch programs are elements of this environment.

Before considering possible environmental interventions, you first need to assess what environmental factors are contributing to excessive child weight gain in these categories and domains.

Environmental Factors Contributing to Excessive Child Weight Gain - Examples

For example,

1. Having only soda or sports drinks available at a sporting event is an example of a factor related to the built environment that can be a barrier to healthier beverage choices.
2. Finding the school gym locked after school shows how the availability of a facility can affect physical activity options.
3. When the typical snack parents bring to day care is cookies or cupcakes, changing to healthier snack options can be difficult.
4. Getting a child to walk to school when all of her friends get rides can be difficult since the social environment is so important to kids.
5. The cost of fresh fruits and vegetables can be a factor related to the economic environment that prevents some families from eating more produce.
6. Spending money on a new bicycle may not always be feasible, and this factor limits ways some children can be physically active.
7. Vending machine policies that limit availability of soda but not fruit drinks may make it difficult to decrease sweetened beverage consumption.
8. If school policy does not require daily physical education, then students are unlikely to be active each day at school.

Once you've identified some environmental factors that could be serving as barriers to healthy eating and active living, then it's easier to identify appropriate environmental interventions. Let's consider some possible interventions.

Environmental Interventions to Prevent Obesity - Examples

1. Providing water at a sporting event instead of soda, sports drinks, or other caloric drinks is an example of an intervention that would change the built environment--the availability of foods and drinks--to encourage healthy eating.
2. Making the school gym available to the community in the evening changes the built environment to encourage more active living.
3. To encourage healthy eating, you might try to influence the social climate that dictates what kinds of snacks parents are expected to bring to day care.
4. You might influence the social climate for exercise by creating a walk-to-school program.
5. Reducing the cost of healthy foods--for example via subsidies, cooperatives, or the encouragement of grocers to decrease their margins on certain foods--improves the economic environment for healthy eating.
6. Making bicycles available more affordably affects the economic environment to encourage active living.
7. An example of a policy environment intervention that would encourage healthy eating is setting nutrition requirements for foods sold in school vending machines.
8. An example that would encourage active living is requiring a minimum number of hours of physical education classes every week.

These kinds of environmental interventions can happen at several different levels of the community, for example, at the town, the neighborhood, and the home levels. Organizations, such as schools, day care centers, the workplace, sports teams, and social clubs, are also good targets for environmental interventions.

Impacting the Environment

a. Think globally.

Many environmental factors that impact food choices and physical activity, particularly at the national policy level, seem to be beyond our reach for changing. And it's true that, alone, you are unlikely to be able to revise FDA guidelines, halt urban sprawl, or stop the marketing of fast food to children.

But, as health professionals, we can collaborate with elected officials, government policy makers, and health promotion organizations. Also, national policy changes can be influenced by the groundswell of local changes across many communities. Most of us are in a good position to influence environmental changes at the local level.

b. Act locally.

An ecological approach to preventing childhood obesity includes assessing environmental factors at the local level so intervention strategies can be more effective. This course focuses on how you can intervene in your community to make it easier for children to make healthy eating choices and live actively and, by doing so, to contribute to the movement promoting healthy eating and active living across the country.

¹ Hill JO, Peters JC. Environmental contributions to the obesity epidemic. Science. 1998;280(5368):1371-1374.

² Jago R, Branowski T. Non-curricular approaches for increasing physical activity in youth: A review. Prev Med. 2004;39:157-163.

³ Huston SL, Evenson KR, Bors P, Gizlice Z. Neighborhood environment, access to places for activity, and leisure-time physical activity in a diverse North Carolina population. Am J Health Promot. 2003;18:58-69.

⁴ Giles-Corti B, Macintyre S, Clarkson JP, Pikora T, Donovan RJ. Environmental and lifestyle factors associated with overweight and obesity in Perth, Australia. Am J Health Promot. 2003;18:93-102.

⁵ Saelens BE, Sallis JF, Black JB, Chen D. Neighborhood-based differences in physical activity: An environment scale evaluation. Am J Public Health. 2003;93:1552-1558.

⁶ Sundquist J, Malmström M, Johansson SE. Cardiovascular risk factors and the neighborhood environment: A multilevel analysis. Int J Epidemiol. 1999;28:841-845.

⁷ Centers for Disease Control and Prevention. StairWELL to Better health: A Worksite Intervention. Available at: http://www.cdc.gov/nccdphp/dnpa/stairwell/index.htm. Accessed December 5, 2005.

⁸ Centers for Disease Control and Prevention. Guide to Community Preventive Service: Systematic Reviews and Evidence-Based Recommendations. Available at: http://www.thecommunityguide.org. Accessed December 5, 2005.

⁹ Department of Health and Human Services. Guidelines for school and community programs to promote lifelong physical activity among young people. Morb Mortal Wkly Rep. 1997;46:1-36.

¹⁰ French SA, Story M, Jeffery RW. Environmental influences on eating and physical activity. Annu Rev Public Health. 2001;22:309-335.

¹¹ Morland K, Wing S, Diez Roux A, Poole C. Neighborhood characteristics associated with the location of food stores and food service places. Am J Prev Med. 2002;22(1):23-29.

¹² Centers for Disease Control and Prevention. Making it Happen: School Nutrition Success Stories. 3/28/2005. Available at: http://www.cdc.gov/healthyyouth/nutrition/Making-It-Happen/index.htm. Accessed December 5, 2005.

¹³ Egger G, Swinburn B, Rossner S. Dusting off the epidemiological triad: Could it work with obesity? Obes Rev. 2003;4:115-119.