Identifying Causes and Prevention Strategies for Obesity using a Multilevel Model of Health

World Health Organization defines overweight as a body mass index (BMI) greater than or equal to 25, and obesity as a BMI greater than or equal to 30 (WHO, 2018). According to WHO, in 2016, 39% of adults world-wide were found to be overweight, and 13% of the worlds adult population were obese (WHO, 2018). This figure is triple what it was in 1975 (WHO, 2018). Obesity is a problem because it is a major risk factor for several non-communicable diseases including cardiovascular disease, heart disease, stroke and diabetes (WHO, 2018). In addition, it can have psychological effects, and is a risk factor for musculoskeletal disorders, such as osteoarthritis (WHO, 2018). The cause of the obesity epidemic is more complex than simply poor nutrition and lack of activity (Jacob & Jutka, 2015). It is a health condition that must be examined using a multilevel model so that determinants of behaviours like nutrition and physical activity can be better understood (Jacob & Jutka, 2015). An appropriate place to start is for example, learning how different features of the built economic or social environment contribute to or constrain healthy eating and physical activity (Huang, Drewnosksi, Kumanyika, & Glass, 2009).

Social ecological models of health describe health issues in terms of environmental and social factors that influence human behaviours and health outcomes (Jacob & Jutka, 2015). The downstream cause of obesity is an imbalance of energy consumption and expenditure (Huang et al., 2009). This imbalance is caused by biological susceptibilities and socioenvironmental factors which, according to recent evidence in behavioural economics, are often outside of an individual’s rational control (Huang et al., 2009). In October of 2007, a conference called “Beyond Individual Behavior: Multidimensional Research in Obesity Linking Biology to Society” was held (Huang et al., 2009). The goal of the conference was to support multilevel research related to obesity, and to create solutions on the macro and micro level (Huang et al., 2009). On the macro level, the discussions included policies related to food, as well as, physical, social and economic environments (Huang et al., 2009). On the micro level, the focus was on individuals, and their immediate environments (Huang et al., 2009). The conference presented obesity as a complex systems problem that requires cross-disciplinary questions and hypotheses, as well as building capacity for multilevel research and action (Huang et al., 2009). The social ecological model presented by Mcatee and Glass at the conference included biological factors such as genetics, and socioenvironmental factors, such as social networks, culture and economics (Huang et al., 2009). The model is multilevel because the factors in the model can interact, and can constrain or encourage certain health behaviours (Huang et al., 2009). For example, food choices may be made because of price, cultural meaning, flavour, and/or availability of food (Huang et al., 2009).

The relationship between economic factors and obesity was demonstrated in a multilevel study on health outcomes in youth (Schreier & Chen, 2013). The study found that low socioeconomic (SES) status was associated with increased rates of obesity and asthma, even in countries like Canada, where there is universal healthcare (Schreier & Chen, 2013). The study noted that violent neighbourhoods shaped parenting styles and parent mental health (Schreier & Chen, 2013). This was significant because mental health in parents, and parenting behaviours were linked to health outcomes in their children (Schreier & Chen, 2013). It was found that more violent neighbourhoods contributed to post-traumatic stress in youth, behavioural problems, and depressive symptoms (Schreier & Chen, 2013). These psychological issues were associated with higher rates of obesity and asthma (Schreier & Chen, 2013). The study found that noise pollution, including traffic and aircraft noise affected youth quality of life and perceived stress, negatively (Schreier & Chen, 2013). Factors on different levels such as community, family and personal levels influenced each other in dynamic ways (Schreier & Chen, 2013). Figure 1, which is reprinted from the study by Schreir & Chen, helps to illustrate this relationship.

Figure 1 “Proposed pathways between socioeconomic status and youth health outcomes (Schreier & Chen, p. 608, 2013).” Reprinted from ‘Socioeconomic Status and the Health of Youth: A Multilevel, Multidomain Approach to Conceptualizing Pathways.’ Psychological Bulletin, 139(3), 606–654.

In figure 1, you can see that the family physical and social influences can be bidirectional feedback loops on each other that increase their impact on youth health (Schreier & Chen, 2013). For example, pollution in the environment, and lack of resources impacts parenting and stress within the family unit, and together they impact a child’s psychological state. As a result, the child has more barriers to face when trying to establish healthy behaviours such as good nutrition and exercise. The figure illustrates how all these factors can work synergistically to make a greater impact (Schreier & Chen, 2013).

In British Columbia (BC), where I live, 20.4% of Canadians are obese (Statistics Canada, 2015). This is compared to the national average, which is approximately 25% (Statistics Canada, 2015). In order to address the growing problem of obesity in BC, a continuum was created. This continuum involved planning, partnership, and action between multiple sectors, and at multiple levels (Bradbury, Day & Scarr, 2015). The continuum includes population health, prevention, identification, early intervention, weight management and specialized treatment (Bradbury et al., 2015). Each part of the continuum has a goal and then initiatives to help achieve that goal.

The population health goal was to improve social environments so that they support healthy eating and active lifestyles. A second goal was to reduce health disparities and vulnerabilities (Bradbury et al., 2015). An example of an initiative to achieve the population health goal is ‘Plan H,’ which seeks to initiate partnerships across many sectors, including health authorities and local governments (Bradbury et al., 2015). The aim of Plan H is to improve communities through policy changes, plans and collective action (Bradbury et al., 2015). Plan H focuses on creating healthy people, societies, and environments (Bradbury et al., 2015). More specifically, Plan H seeks to improve the air we breathe, housing we live in, food we can access, green space availability and safety of our neighborhoods (Bradbury et al., 2015).

In the prevention part of the continuum the first goal is to educate people about making healthy choices; the second is to create environments that encourage physical activity, healthy eating and mental wellbeing (Bradbury et al., 2015).

Healthy Families BC is BC’s chronic disease prevention and promotion strategy (Bradbury et al., 2015). It provides a framework for promoting and improving health, and encourages action throughout the province at every level (Bradbury et al., 2015). One example of an initiative is ‘Farm to School,’ a program that is carried out by the Public Health Association of BC (Bradbury et al., 2015). Schools can be connected with local farmers so that fresh produce is available for them to eat in school during the day. The program also helps to educate youth and children about local farming (Bradbury et al., 2015).

Identifying weight related issues in the early phases, so that interventions can be made early is important because early interventions often mean a better chance of a healthy outcome (Bradbury et al., 2015). BC is the first province to use growth charts for monitoring weight and identifying children who are leaving their optimal weight trajectory (Bradbury et al., 2015). World Health Organization developed these growth charts. The point of this identification is so that these children can be referred to programs that will support them in getting back to a healthy weight early on (Bradbury et al., 2015).

Prevention initiatives have mainly focused on environmental factors thus far, however there are other complex factors that can influence obesity and physical health. For example, mental health, social isolation and depression can influence obesity (Bradbury et al., 2015). There is not one single causal factor to obesity, so it is unlikely that a single intervention will have any notable impact (Jacob & Jutka, 2015). A portfolio of continuous interventions, which rely less on education and personal responsibility, and more on reshaping societal norms and improving environmental factors is needed in the fight to prevent obesity (Jacob & Jutka, 2015). The interventions that are necessary are the ones that make eating healthy and exercising a natural, and simple way of living (Huang et al., 2009).

References

Bradbury, J., Day, M., & Scarr, J. (2015). British Columbia’s Continuum for the Prevention, Management, and Treatment of Health Issues Related to Overweight and Obesity in Children and Youth. Retrieved on October 24, 2018 from http://www.childhealthbc.ca/sites/default/files/15%2012%2018%20Healthy%20Weights%20Continuiim.pdf

Huang, T. T., Drewnosksi, A., Kumanyika, S., & Glass, T. A. (2009). A systems-oriented multilevel framework for addressing obesity in the 21st century. Preventing chronic disease, 6(3), A82.

Jacob C., S., & Jutka, H. (2015). The Global Burden of Obesity and the Challenges of Prevention. Annals of Nutrition and Metabolism, 7. https://0-doi-org.aupac.lib.athabascau.ca/10.1159/000375143

Schreier, H. M. C., & Chen, E. (2013). Socioeconomic Status and the Health of Youth: A Multilevel, Multidomain Approach to Conceptualizing Pathways. Psychological Bulletin, 139(3), 606–654.

Statistics Canada. (2015). Health at a glance. Retrieved on November 1, 2018 from https://www150.statcan.gc.ca/n1/pub/82-624-x/2014001/article/11922-eng.htm

World Health Organization. (2018) Obesity and Overweight. Retrieved on November 26, 2018 from http://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight