Health and liveability

Week 6:                    Planning for Health – Built Environment and Nutrition

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Introduction

Last week this course examined physical activity in relation to the built environment and this week we are going to focus on nutrition and healthy eating, with a particular focus on obesity, and how those are influenced by place-based variables.  The built environment impacts health through food access and availability at the neighborhood level.  We will define neighbhorhood broadly as “the area around one’s place of residence” (Larson, Story, & Nelson, 2009).

As you know by now, research over the past 20 years has confirmed the importance of social, economic, environmental, and cultural factors, collectively known as social determinants of health, in driving and sustaining health disparities (Braveman, Egerter, & Williams, 2011; Link & Phelan, 1995; D. R. Williams & Collins, 1995). For example, people residing in poor neighborhoods are more likely to become obese than those living in non-poor neighborhoods (Lippert, 2016). Although the proximal determinants of obesity—diet and physical activity—are well known, it is becoming widely recognized that complex social factors, such neighborhood  living conditions, which impact diet and physical activity practices, influence the population distribution of obesity (Bennett, Wolin, & Duncan, 2008).

Place-based social determinants are important for an individuals’ diet practices (Bennett et al., 2008). Neighborhood living conditions influence dietary intake patterns by shaping the choices and opportunities to make healthy dietary decisions. We are going to focus on three variables that research has shown impact the health of neighborhood residents: availability of supermarkets, prevalence of fast food restaurants, and residential racial/ethnic segregation.

Availability of Supermarkets

In cross sectional studies, residents of neighborhoods with more supermarkets have healthier diets and lower rates of obesity than those with fewer (Larson et al., 2009; Zenk et al., 2005).  An important reason for this may be that in comparison to other types of stores that carry food, such as convenience stores, supermarkets offer the best variety of high-quality foods at the lowest prices.  Communities with poor access to supermarkets are called food deserts or low access communities. According to the USDA, a food desert (or low access community) is where at least 500 people and/or at least 33 percent of the census tract’s population reside more than one mile from a supermarket or large grocery store. For rural census tracts, the distance is more than 10 miles.  People who live in food deserts tend to have less access to healthy foods that are affordable, such as fresh fruits and vegetables, whole grains, lean meats and low fat dairy products.

However, more research is needed to examine whether residents who live in areas classified as food deserts have diets of poor quality because of their lack of access to affordable, healthy foods or because of their personal preferences. In the first controlled study undertaken in the U.S. on access to supermarkets and food intake, Cummins, Flint, and Matthews (2014) found that when a new grocery store was opened in a food desert in Philadelphia, there were no changes residents’ fruit and vegetable intake or BMI.  Therefore, complementary policy changes and interventions may be needed to help residents improve their consumption of fruit and vegetables even when access is improved.  Hilmers et al. (2012) suggest that community sociocultural perceptions related to food and barriers to healthful dietary practices should be assessed and strategies implemented to remove those barriers.

Prevalence of Fast Food Restaurants

People who live in food deserts, especially those who have limited transportation options, often must rely on convenience food stores and fast food restaurants, both of which offer limited selections of healthy foods.  Research indicates that presence of fast food restaurants and convenience stores creates an increased risk for obesity at the community level (Alviola, Nayga, Thomsen, Danforth, & Smartt, 2014; Larson et al., 2009; Maddock, 2004; Mehta & Chang, 2008).

Residential Racial/Ethnic Segregation

Urban, low income and minority neighborhoods have been found to have less access to healthy foods and racial/ethnic minorities are more likely than whites to live in areas that are classified as food deserts (Morland, Wing, Diez Roux, & Poole, 2002; Powell, Slater, Mirtcheva, Bao, & Chaloupka, 2007; Zenk et al., 2005).  Further, research has found that there is a greater prevalence of fast food restaurants in low income minority neighborhoods (Larson et al., 2009) The inadequate built environment related to food access is made worse by the fact that transportation options are limited among low income residents (David R Williams & Collins, 2001).  The lack of access may contribute to a poor diet and can lead to higher levels of obesity and other diet-related chronic diseases.

Neighborhoods with a majority of black residents have greater rates of obesity than those with more white residents (Boardman, Saint Onge, Rogers, & Denney, 2005; Robert & Reither, 2004). However, race-based obesity disparities are diminished when controlling for neighborhood characteristics (Bleich, Thorpe, Sharif-Harris, Fesahazion, & LaVeist, 2010; Boardman et al., 2005; LaVeist, Pollack, Thorpe, Fesahazion, & Gaskin, 2011). At the individual level, perceived discrimination and internalized racism may also play a role in obesity (D. R. Williams, Mohammed, Leavell, & Collins, 2010).

To examine the above 3 variables in greater context, Storey (2008) has posited an ecological framework to guide both research and interventions related to dietary consumption. An ecological model emphasizes the connections between people and their environments and how multilevel factors interact to influence health and nutrition.

In summary, neighborhood living conditions structure choices and opportunities in terms of nutrition:

• Residents of neighborhoods with more grocery stores have healthier diets and lower rates of obesity in comparison to those with fewer.
• Fast-food restaurants may create an increased risk for obesity at the community level.
• Urban, low income and minority neighborhoods have been found to have less access to healthy foods and greater prevalence of fast food restuarnts; and, racial/ethnic minorities are more likely than whites to live in areas that are classified as food deserts.

Learning Outcomes

By then end of this week’s activities you should be able to:

1. Explain how neigbhorhood living conditions related to food access and availability may impact health.
2. Describe how racial/ethnic segregation is related is food access and availaility
3. Use USDA databases for creating maps of food deserts and other food environment variables in specified locales.