According to “Global Burden of Disease: Country Profile,” a study conducted in 2014 by the Institute for Health Metrics and Evaluation, the top three risk factors for the burden of disease in Korea in 2013 were “tobacco smoking,” “poor diet,” and “alcohol use.” “Lack of exercise” came in 8th on the list. “Smoking cessation,” “alcohol abstinence,” “physical exercise,” and “nutrition” are among the core areas of the “Community-based Integrated Health Promotion Project,” and their indicators are being managed to represent the project on “Healthy Lifestyle Practice” in the framework of the 4th National Health Plan (2016~2020). Income-related disparities in these four areas have been designated as health equality indicators in the 4th National Health Plan. However, the health equality indicators in the Health Plan concern health disparities with respect to only income, and the top and bottom income levels at that. For this reason, social gradients1 in health in the context of the 4th National Health Plan are not as evident as they should otherwise be, and fail to capture the full extent of health disparities across different socioeconomic strata. It is widely known that people have different levels of health depending on their socioeconomic positions. The better off people are, the more likely they are to live longer in better health. For centuries, a wide range of approaches have revealed the direct association of health with socioeconomic positions, with numerous epidemiological studies consistently showing that morbidity and mortality differ across people of different socioeconomic strata. This study defines its unhealthy lifestyle indicators in terms of “current smoking,” “high-risk drinking,” “no muscle exercise,” and “food insecurity” (“the state of being without reliable access to a sufficient quantity of affordable, nutritious food”).2 The subjects of this study are grouped into four clusters: those with no unhealthy lifestyle habit; those with one unhealthy lifestyle habit; those with two unhealthy lifestyle habits; and those with three unhealthy lifestyle habits.
