MEASURES REGISTRY USER GUIDE
Measuring Food Environments
Why Study the Food Environment?
Over the past few decades, public health researchers and practitioners have become increasingly interested in the influence of the food environment on health-related outcomes. Many studies have sought to elucidate the relationship between the food environment and obesity, dietary patterns, chronic disease, and other health-related factors.1-5 Furthermore, numerous agencies, including the World Health Organization,6 the Institute of Medicine,7 and the Centers for Disease Control and Prevention (CDC),8 have identified interventions targeting changes in the food environment as strategies for creating population-wide improvements in dietary patterns and weight status. For obesity researchers and public health practitioners working toward effective community level approaches to reduce the incidence and prevalence of obesity, the food environment is recognized as an important piece of the puzzle in understanding population-level obesity risk.9 Thus, considering how the food environment is assessed becomes critically important. Robust measures of the food environment are needed in order to: (1) differentiate obesity risk between and within population groups, and (2) evaluate the effectiveness of interventions (either natural experiments or planned environmental change) to bring about change. The NCCOR Measures Registry and User Guide is intended to support and encourage the use of food environmental approaches for reducing obesity risk by providing information and sources of robust measures of the food environment.
Defining Food Environments
The food environment includes the physical, social, and person-centered environments that play a role in what people choose to eat. This Guide will focus largely on how the food environment affects children and adolescents and the adults that care for them.
The physical food environment includes the availability and accessibility of foods in homes, early care and education centers, preschools, schools, and community venues such as community centers or recreational facilities. The most proximal physical environment influencing youth food intake is the availability of and accessibility to foods in their homes. At more distant levels, the food that is available to schools and other community venues that serve children also influences what youth can eat, including foods available through government commodity programs as well as from local distributors. The physical environment also includes the availability and accessibility of foods in neighborhoods, the presence of food information (e.g., nutrition labels and shelf call-outs), and advertisements in stores and restaurants.
Influential aspects of the physical food environment change as children age. Younger children are dependent upon the adults who care for them to provide foods; therefore, understanding the physical environment in which their families live and procure food becomes an element of the food environment that impacts youth. As children mature, the choices made available to them expand and they become more autonomous in their food choices. As early as elementary school, á la carte cafeteria lines become available to many students, and by middle and high school, students are choosing their meals at school from a vast array of options including vending machines, pizza lines, and sandwich grills. As children start spending time at friends’ homes and participating in community activities such as sports teams, the food environment to which they are exposed becomes less under the control of parents. Youth also have direct access to many food options in their communities, including food available at convenience stores, corner stores, and fast food restaurants. These become important venues in which youth make food choices and constitute an important aspect of their physical food environment.
The food environment also includes the social environment including social support for making healthy food choices; role modeling and social expectations regarding food choices; food choice incentives or rewards as part of marketing strategies or as an attempt to influence behavior; and policies, practices, or rules about eating behaviors. Social support for healthy food choices may come from peers, parents, teachers, or other adults, and may include helping youth learn how to prepare healthy snacks or congratulating youth on making healthy choices. Modeling of eating behaviors is particularly important for youth since they are learning (often in very subtle ways) about what, when, how much, and why to eat from the larger culture, people that they interact with in their communities, and, more proximally, families, friends, and peers. Role models communicate through their actions normative expectations regarding preferred food choices and eating practices of the social group. The social environment also includes marketing strategies that include incentives and rewards for food choices that may come in the form of foods and beverage gifts with purchase or redeemable prizes from the food industry or local stores, the use of foods as rewards and incentives by school personnel, or family practices that attempt to shape behavior through the use of foods. This social environment also includes prescriptive or prohibitive rules about what, when, and where to eat and drink that are imposed by family rules around meal time and eating behavior by school administrators and teachers through school policy, and by food-related policies set by community agencies. When policies and practices are implemented consistently, the physical environment is changed. Distally, food policy at the national level may be seen as part of the social environment that affects youth. Measures exist for assessing environments in each of these settings although some gaps remain, as outlined later in this Guide.
Finally, the food environment also includes a person-centered element which is represented by an individual’s perceptions of the food environment and their own relationship with food. There is good evidence that one’s perceptions of the food environment are as important, if not more important, than objective measures of the physical food environment.2,10,11 Similarly, youths’ attitudes toward foods, including such factors as taste preferences, perceived barriers to eating healthy foods, and perceived self-efficacy regarding making healthy food choices may be more important than factors related to both the physical and social environment. Although attitudes that affect motivation, personal taste preference, and self-regulation are all important person-centered factors that influence eating behavior, this Guide will focus on measurement of the perceived social and physical environments as key elements of the person-centered environment.
Figure 2 is a conceptual model that includes these three major domains of the food environment (physical, social, and person-centered) arranged in a causal model suggesting how each of these domains are related to each other and to health outcomes of interest (food choice behaviors, dietary intake, and diet-related disease). Measures of the food environment can be conceptualized as fitting into one of these three broad categories and will be described in Section 3.
Figure 2: Conceptual Model of Environment Factors Related to Dietary Disease Risk
This model suggests that the physical and social environments are directly related to food choices of individuals but that some of their effect is indirect, mediated by factors in the person-centered environment. This model also stresses that the person-centered environment of the individual is the most proximal set of influences on choosing foods. Although individuals’ choices are influenced by foods available in their physical environment and elements of the social environment, most individuals are left with a great deal of autonomy in what they choose to eat.
This conceptual model (Figure 2) also emphasizes the importance of the hypothesized link between the food environment and health outcomes. Showing these simple relationships highlights the implied association between environmental factors and diet-related outcomes (the association that is examined by testing construct validity) as well as the assumption of causality or the belief that a change in the environment will effect change in food choices. The assumption of causality is important. Researchers and public health practitioners care about elements of the food environment because they believe that they are related to health and, once understood, can be changed through programs or policies to improve the health of populations. Without that link to health behavior, an assessment of the environment is a poor use of limited resources.
As one considers how to use the Measures Registry to guide which measures to use, this conceptual model may help the user think through such issues as:
- What aspect of the food environment do I need to study for the particular purpose of my study or practice question? Am I most interested in:
- Aspects of the physical environment? (If so, in what venue?)
- The social environment? (If so, what aspect of the social environment?)
- Individuals’ perceptions of the environment?
- Is my purpose to describe multiple aspects of food environments (choosing elements from each of the physical, social, and person-centered domains) to understand food choices of a population group, or am I attempting to examine one aspect of the environment that has already been linked to a behavioral or health outcome in a particular setting?
- If the physical environment is selected, what venues do I want to assess?
- Do I want to assess stores, restaurants, schools, or homes?
- Do I have adequate resources to collect data through geographic analyses or environmental scans or observations?
- How do I obtain access to protected or private spaces, such as schools or homes?
- What aspect of the retail food environment is most important for me to assess?
- If the social environment is selected, what aspect of the social environment and what social connections are most important to assess?
- Do I have the resources to collect eating behavior information on parents or peers?
- Is a measure of social norms or social support important to my purpose?
- How will I get access to and sample elements of the social environment that I care about?
- If I want to predict behavior, person-centered factors are likely important.
- How will I assess perceptions of the food environment?
- Do I need to use both qualitative and quantitative approaches to understand the ways that individuals perceive their food environment?
- Is my purpose to describe the association between the food environment and food choices, dietary intake, or a health outcome; or is it to test the effects of some intervention? If it is an intervention study:
- What aspects of the environment will my intervention target?
- What environmental factor can my intervention realistically change based on my resources and timeframe of my study?
Section 3 of this Guide provides some information on key concepts that can assist in making these decisions.