Public health is defined by its focus on prevention and on the health of populations, rather than individuals. It takes a systematic approach to problem solving that includes reviewing evidence (data) to determine the existence, scope and magnitude of a problem, and it uses models and theories to explain the rationale behind its interventions. In this appendix, we explain some of the models and theories behind the priority recommendations in the plan.
A Social Ecological Perspective
Researchers suggest that the recent rise in obesity rates are due to changes in the physical, social, and economic environments that make it increasingly harder for individuals to get the activity and health promoting foods that they need. This “obesogenic” environment is “the sum of influences that the surroundings, opportunities, or conditions of life have on promoting obesity in individuals or populations.”(1) In an obesogenic environment, food marketing, media, federal and state policies related to food and agriculture, urban design, education, and transportation work together to constrain healthy eating and physical activity in communities, worksites, homes and schools.(1)
To reverse growing rates of obesity, people will need to balance energy intake (nutrition) and output (physical activity). Yet human behavior is difficult to change, particularly in an environment that does not support change. This is why even the best individual weight loss programs are hard to sustain.(2) In order to increase physical activity and healthy eating, health promotion efforts need to focus not only on the behavior choices of each individual, but also on factors that influence those choices.(3) These factors operate out of several spheres of influence, including public policy, institutional/ organizational, community, interpersonal as well as individual levels. This social ecological perspective helps us to pinpoint opportunities for promoting health by understanding the factors that influence behavior at each level of the social ecological model (shown above) and by recognizing that an individual’s behavior both shapes, and is shaped by, multiple levels of influence.
Efforts to change health behavior are more likely to be successful when we work within multiple spheres of influence at the same time. (3) For example, we can increase the knowledge, skills, and self efficacy of low-income individuals to adopt healthy nutrition habits through demonstrations and classes offered by the Basic Food Nutrition Education program. In family-centered programs such as those offered by the Early Childhood Education and Assistance Programs in Washington, we can increase interpersonal support for healthy nutrition and active lifestyles. At the institutional level, we can make it easier for individuals to change health behaviors by encouraging employers to implement policies that support walking or biking to work. At the community level, we can encourage physical activity by enhancing pedestrian safety. At the social structure level we can work with transportation and urban planning experts to develop city plans that make it easier for citizens to walk or bike to work, libraries, churches, schools, entertainment, shopping and other services.
The social ecological perspective, described above, suggests that interventions at multiple levels of the model are needed to address obesity. This section describes the factors that researchers have linked to obesity at each level of the social ecological model.
- Physiology includes a mix of biological variables e.g. genetic predisposition to obesity, level of satiety and resting metabolic rate.
- Individual activity consists of an individual’s level of recreational, occupational and transport activity, as well as the learned activity patterns. Researchers have found that the higher one’s fitness level, the easier it is to engage in physical activity, and vice versa.
- Individual psychology includes factors such as self-esteem, personal stress, and level of ‘food literacy’.
Organizations and Public Policy:
- Environment for physical activity includes the cost of physical activity, perceived safety and walkability.
- Food consumption includes many characteristics of the food market in which consumers operate such as the level of food abundance and variety, the nutritional quality of food and drink, energy density of food, and portion size.
- Food production includes drivers of the food industry such as pressure for growth and profitability, market price of food, and effort to increase efficiency of production.
- Social psychology factors include education and media availability. It also includes variables related to societal attitudes to weight such as the importance of ideal body-size image.
Using Theory to Guide Interventions
As described above, interventions could be developed to change influential factors at each level of the social ecological model. Theories have been developed to describe the mechanisms by which interventions at each level of the social ecological model change influential factors, resulting in more supportive environments and healthier physical activity and nutrition behaviors. The following theories help explain how the priority recommendations of the plan work to achieve its six objectives, as well as its overarching goals.
Theories Governing Individual Behavior Change
A number of theories have been developed to describe how changes in factors at the individual and interpersonal levels of the social ecological model work.* These theories can be broadly characterized as cognitive behavioral theories, and share the following key concepts:
- What people know and think affects how they act.
- Knowledge is necessary, but not sufficient to produce most behavior changes.
- Perceptions, motivations, skills and social environment are key influences on behavior.
Some well-known cognitive behavioral theories:
- The Health Belief Model, (HBM) HBM addresses the individual’s perceptions of the threat posed by a health problem (susceptibility, severity), the benefits of avoiding the threat, and factors influencing the decision to act (barriers, cues to action, and self-efficacy.
- The Stages of Change (Transtheoretical) Model The Stages of Change Model describes individuals’ motivation and readiness to change a behavior.
- The Theory of Planned Behavior (TPB) The TPB examines the relations between an individual’s beliefs, attitudes, intentions, behavior, and perceived control over that behavior.
- The Precaution Adoption Process Model (PAPM) The PAPM names seven stages in an individual’s journey from awareness to action. It begins with lack of awareness and advances through subsequent stages of becoming aware, deciding whether or not to act, acting, and maintaining.
Theories Governing Social Change
- Social Cognitive Theory (SCT) The SCT describes a dynamic, ongoing process in which personal factors, environmental factors, and human behavior exert influence upon each other.
- Community Organization and Other Participatory Models emphasize community-driven approaches to assessing and solving health and social problems.
- Diffusion of Innovations Theory The Diffusion of Innovations Theory addresses how new ideas, products, and social practices spread within an organization, community, or society, or from one society to another.
- Communication Theory The Communication Theory describes how different types of communication affect health behavior.
Taken together, these theories can be used to influence factors within each level of the social ecological model in the followings ways:
- Individual: health education strategies use behavior change theory to influence awareness, knowledge, attitudes.
- Interpersonal: family, friends, peers that provide social identity and support.
- Organizations: organizational change, diffusion of innovation, and social marketing strategies.
- Community: social marketing, community organizing.
- Public Policy: public opinion process, policy change process.
The Role of Public Health in a Comprehensive Approach
Behavioral scientists have turned their attention to finding effective ways to change our obesogenic environment. Policy changes in the realms of education, food labeling and advertising, food assistance programs, health care and training, transportation, urban development, commerce and taxation can lead to improvements in nutrition and activity patterns.
Any one profession, institution, or agency alone can not do this work. In developing and implementing this plan we are following these recommended steps: (2)
- Form a state-based coordinating group to develop policy on nutrition and physical activity.
- Identify opportunities to reallocate existing resources from ongoing initiatives in other sectors that are in line with nutrition and physical activity policy priorities.
- Educate leaders and provide guidance to decision makers about nutrition and physical activity issues.
Public health can provide leadership to this work. The three core functions of public health can be directly applied to the efforts of this plan. The process is to assess the barriers to healthy food and activity choices that contribute to the obesogenic environment; then develop policies that address barriers and enhance opportunities to choose healthy behaviors; and finally, to assure that all Washington State citizens have access to health-promoting environments.
One of the primary responsibilities of public health is to minimize the effects of societal and economic constraints that lead to health disparities. Environment and policy interventions have the potential to reach all residents of the state. State and community-level decisions have, over time, inadvertently resulted in communities where it is often difficult to be physically active and to make healthy food choices. This becomes especially troublesome for children, the elderly, the disabled, and the poor for whom transportation is an issue. One role of the Washington State Department of Health is to perform the policy development and assurance functions of public health by encouraging the institutions, agencies, and communities of Washington State to consider the effects on health and well being of all citizens as they make policy and planning decisions.
In focusing on environmental and policy approaches in this plan, Washington State joins a national movement to seek out and address the root causes of the rapid increase in obesity. The following national guidelines, and many others, emphasize the importance of policy change:
- The National Governor’s Association Center for Best Practices: The Obesity Epidemic – How States can “Trim the Fat” (4)
- The Surgeon Generals’ Call to Action to Prevent and Decrease Overweight and Obesity(5)
- The Centers for Disease Control and Prevention: The Guide to Community Preventive Services – Physical Activity(6)
- The American Heart Association: Guide for Improving Cardiovascular Health at the Community Level(7)
- The Nutrition and Physical Activity Workgroup: Guidelines for Comprehensive Programs to Promote Healthy Eating and Physical Activity(8)
- The Society for Nutrition Education: Guidelines for Childhood Obesity Prevention Programs: Promoting Healthy Weight in Children(9)
- The American Academy of Pediatrics: Promoting Physical Activity(10)
- The U.S. Department of Health and Human Services: Healthy People 2010 (Appendix C)
- Institute of Medicine: Proventing Childhood Obesity: Health in the Balance(11)
* To some extent these theories also explain how change works at the organizational and policy level because institutions and policy making systems are composed of individuals.
- Swinburn B, Egger G, Raza F. Dissecting obesogenic environments: the development and application of a framework for identifying and prioritizing environmental interventions for obesity. Prev Med 1999; 29:563-570.
- Kumanyika SK. Mini symposium on obesity: overview and some strategic considerations. Annu Rev Public Health 2001;22:293-308.
- Gregson J, Foerster S, Orr R, Jones L et al. System, environmental, and policy changes: Using the Social-Ecological model as a framework for evaluating nutrition education and social marketing programs with low-income audiences. J Nutr Ed 2001;33(Suppl 1):S4-15.
- The National Governor’s Association Center for Best Practices. The Obesity Epidemic – How States CanTrim the “Fat.” Washington, DC: National Governor’s Association, 2002. [Online]. Available: http://www.nga.org/files/live/sites/NGA/files/pdf/OBESITYIB.pdf
- U.S. Department of Health and Human Services. The Surgeon Generals call to action to prevent and decrease overweight and obesity. Rockville, MD: U.S. Department of Health and Human Services, Public Health Service, Office of the Surgeon General, 2001. Available from: U.S. GPO, Washington.
- Centers for Disease Control and Prevention. The Guide to Community Preventive Services. [Online]. Available: http://www.thecommunityguide.org
- Pearson TA, Bazzarre T, Daniels S, Fair JM, Fortman SP, Franklin BA et al. American Heart Association Guide for Improving Cardiovascular Health at the Community Level: A Statement for Public Health Practitioners, Healthcare Providers, and Health Policy Makers from the American Heart Association Expert Panel on Population and Prevention Science. Circulation 2003:107:645-651.
- Gregory, Susanne, ed. Guidelines for Comprehensive Programs to Promote Healthy Eating and Physical Activity. Champaign, IL: Human Kinetics, 2002.
- Weight Realities Division of the Society for Nutrition Education. Guidelines for Childhood Obesity Prevention Programs: Promoting Healthy Weight in Children, 2002. [Online]. Available: http://www.sne.org/
- American Academy of Pediatrics. Promoting Physical Activity. [Online]. Available: http://brightfutures.aap.org/pdfs/Guidelines_PDF/7-Promoting_Physical_Activity.pdf
- Koplan JP, Liverman CT, and Kraak VA, (Eds.). Preventing Childhood Obesity: Health in the Balance, 2005. [Online]. Available: http://books.nap.edu/catalog.php?record_id=11015