13.1: Introduction
The U.S. spends more on healthcare than many other countries (OECD, 2023), and spends far more on healthcare than on public health (Pilar et al., 2020). Yet several of the leading causes of death are strongly influenced by lifestyle behaviors. This has led several researchers to quantify the actual causes of death in terms of behaviors and environmental factors. Prior to the COVID-19 pandemic, actual causes of death in 2017 were identified as the following list, with the percentage of total deaths associated in parenthesis. Note that these percentages will not add up to 100% because there are other causes of death not on this list, and many diseases have multiple causes.
- Poor nutrition (19%)
- Tobacco use (18%)
- Toxic agents (7%)
- Microbial agents (4%)
- Illicit drug use (4%)
- Alcohol use (3%)
- Physical inactivity (3%)
- Firearms (1%)
- Motor vehicles (1%)
- Sexual behavior (1%) (Pilar et al., 2020).
A recent study looked at trends in self-reported healthy behaviors between 1999-2000 and 2017-2020 using data from the National Health and Nutrition Examination Survey (NHANES). Results indicate that over the last few decades, more Americans are avoiding smoking tobacco (57.7%), being physically active at least 150 minutes per week (69.1%), and eating a healthy diet (24.5%). However, we are still gaining weight: those reporting a healthy weight status decreased from 33.1% to 24.6%, and our alcohol consumption has remained about the same. Those who reported 4 or more healthy lifestyle behaviors increased slightly from 15.7% to 20.3%. This study also showed consistent disparities in race and ethnicity, education level, and income level, suggesting that social determinants of health (SDOH) are still powerfully associated with healthy behaviors (Li et al., 2023).
It makes sense then that many community health interventions target changing lifestyle behaviors in a population in order to prevent a disease or injury from occurring in the first place (i.e. primary prevention). In order to effectively change human behavior on a large scale, we need to first understand what makes humans behave the way they do. In this chapter, we will go over a few (not all) of the behavioral change models used in public health practice, as well as community intervention models, and program planning models. At the end of this chapter we will discuss two examples of community interventions targeting physical activity and childhood obesity.