Prevalence of Obesity among Korean Adults Using the Korea Community Health Survey Data

Abstract

Objectives

Obesity is a major public health agenda due to its association with increased risk of chronic diseases and cancer. This study examined the prevalence and trends of obesity among Korean adults using the Korea Community Health Survey data.

Methods

Data from approximately 230,000 adults aged ≥19 years who participated annually in the Korea Community Health Survey between 2015 and 2024 were analyzed. Obesity was defined as a body mass index ≥25 kg/m² based on self-reported height and weight. Annual trends and regional distributions in obesity prevalence were assessed with descriptive statistics, and associations with sociodemographic characteristics were examined using multivariable logistic regression models. All analyses incorporated the complex sampling design and survey weights, and were performed using SAS version 9.4.

Results

In 2024, obesity prevalence among Korean adults was 34.4%, and had increased steadily over the past decade. The prevalence was greater in men (41.4%) than in women (23.0%). Among men, the prevalence of obesity was highest in those aged 30–49 years, while among women, it was higher among those aged ≥60 years. Jeonnam and Jeju had the highest prevalence (36.8%), whereas Sejong had the lowest prevalence (29.1%).

Conclusions

The prevalence of obesity among Korean adults increased steadily over the past decade, with substantial differences by sex, age, and region. Continuous monitoring and targeted prevention and management strategies are needed to address population-specific characteristics.

Key messages

① What is known previously?

Obesity is a major public health agenda because it increases the risk of chronic diseases and cancer, and its prevalence has steadily increased in the Republic of Korea and globally.

② What new information is presented?

In 2024, the prevalence of obesity among Korean adults reached approximately one in three, and it has steadily increased over the course of the past decade. All 17 metropolitan cities and provinces showed increases compared with 10 years earlier. Using Korea Community Health Survey data, this study provides detailed insight into the sociodemographic characteristics associated with obesity and regional disparities.

③ What are the implications?

Evidence-based public health policies that incorporate tailored management strategies based on sociodemographic characteristics and address regional disparities are needed.

Introduction

Obesity is a major public health issue that increases the risk of major chronic diseases, including cardiovascular disease and type 2 diabetes, and its prevalence continues to increase worldwide. According to the World Health Organization (WHO), the number of people with obesity has continued to increase across all regions worldwide. As of 2022, the prevalence of obesity among adults was reported to have more than doubled compared with the early 1990s, indicating that obesity has emerged as a global public health challenge [1]. WHO also identifies obesity as a major risk factor for major noncommunicable diseases and emphasizes the need for systematic national responses and prevention and management through multisectoral collaboration [2].

Global evidence shows that obesity is associated not only with chronic diseases but also with the risk of developing several cancers. The International Agency for Research on Cancer (IARC) reported that excess body fat is causally associated with an increased risk of various cancers, including colorectal, liver, pancreatic, kidney, endometrial, and postmenopausal breast cancers [3]. Evaluation by the IARC Handbooks has shown that the absence of excess body fat might contribute to cancer prevention [4]. Consistently, the World Cancer Research Fund presents maintaining a healthy body weight as a key strategy for cancer prevention [5].

In the Republic of Korea (ROK), obesity is also addressed as a major management priority in national health policy. Through the Sixth National Health Plan (Health Plan 2030), the Ministry of Health and Welfare has set the prevention and management of noncommunicable diseases, including obesity, as a core task and has presented a life-course approach and setting-based strategies as key directions [6]. This policy direction suggests that obesity management should not be limited to individual efforts but should also take social and environmental factors into account.

Thus, this study aimed to provide basic data necessary for establishing future obesity prevention and management policies by using the Korea Community Health Survey (KCHS) data to analyze trends in obesity among adults in the ROK from multiple perspectives, including year, sociodemographic characteristics, and region.

Methods

The KCHS is a nationwide health survey conducted since 2008 pursuant to Article 4 of the Regional Public Health Act. It was designed to systematically assess health behaviors and the levels of chronic diseases at the local level. The statistics produced through this survey are used as scientific evidence for the establishment and evaluation of health policies by the national government and local governments. In this report, obesity prevalence was analyzed using data from approximately 230,000 adults aged 19 years or older who participated in the KCHS each year from 2015 to 2024. The analysis was limited to respondents who answered the survey items on height and weight used to measure obesity prevalence. In the KCHS, self-reported height and weight are collected through a survey to measure obesity prevalence and determine obesity status for each respondent, and obesity is defined as a body mass index of ≥25 kg/m².

This report used a complex sample design analysis method applying weights and stratification variables to represent the characteristics of local residents at the local government level in the ROK. Annual trends in obesity prevalence among all adults in the ROK from 2015 to 2024 were presented as the median of sex- and age-standardized obesity prevalence rates at the public health center level in cities, counties, and districts (using the 2005 projected population of the Ministry of Data and Statistics as the standard population), and obesity prevalence by province and by city, county, and district was also presented as standardized rates. For obesity prevalence by sociodemographic characteristics, crude rates adjusted using national-level average values were used to improve the intuitiveness of level comparisons and interpretation while reflecting the actual distribution of each group. Statistical analyses were performed using PROC SURVEYMEANS in SAS version 9.4 (SAS Institute Inc.).

Results

Obesity prevalence has increased steadily among Korean adults, reaching 34.4% in 2024, indicating that approximately one in three adults has obesity. Compared with the level of approximately one in four adults (26.3%) in 2015, the 2024 data represent an increase of approximately 30.8% (Figure 1) [7].

Figure 1. Trends in obesity prevalence among Korean adults, 2015–2024.

Unit: %, standardized rate. Obesity-related items were not surveyed in 2019; therefore, no obesity prevalence data are available. Reused from Korea Disease Control and Prevention Agency (2025) [7].

Examination of regional trends and patterns in obesity prevalence at the city/province level revealed that the regions with the highest obesity prevalence in 2024 were Jeonnam and Jeju (36.8% each), while the region with the lowest obesity prevalence was Sejong (29.1%) (Figure 2) [7].

Figure 2. Trends in obesity prevalence by province, 2015–2024.

Unit: %, standardized rate. Obesity-related items were not surveyed in 2019; therefore, no obesity prevalence data are available. Reused from Korea Disease Control and Prevention Agency (2025) [7].

Analysis of trends in obesity prevalence at the city/province level over the past 10 years (2015–2024) showed that obesity prevalence increased in all 17 metropolitan cities and provinces nationwide. In particular, Jeonnam showed the largest increase, rising by 11.4 percentage points from 25.4% in 2015 to 36.8% in 2024, followed by Ulsan and Chungnam. In contrast, Sejong showed a relatively moderate increase of 2.9 percentage points over the same 10-year period (26.2% in 2015 to 29.1% in 2024), while Daejeon and Gangwon recorded relatively small increases in obesity prevalence (Figures 2, 3) [7].

Figure 3. Distribution of obesity prevalence by province, 2015 and 2024.

Unit: %, standardized rate. Reused from Korea Disease Control and Prevention Agency (2025) [7].

Average obesity prevalence at the city, county, and district level for the most recent 3 years (2022–2024) was calculated in consideration of the stability of long-term policy effect analysis. The results showed that obesity prevalence was the highest in Danyang-gun, Chungbuk, at 44.6%, followed by Cheorwon-gun, Gangwon, at 41.9%, and Boeun-gun, Chungbuk, at 41.4%. The prevalence was the lowest in Gwacheon-si, Gyeonggi, at 22.1%, followed by Seo-gu, Daejeon, at 23.1%, and Suseong-gu, Daegu, at 23.7%. The disparity ratio between Danyang-gun, Chungbuk, which was at the highest level nationwide (44.6%), and Gwacheon-si, Gyeonggi, which was at the lowest level (22.1%) (defined as “maximum value/minimum value,” with a larger value indicating a greater disparity), was confirmed to be approximately twofold. Variations in obesity prevalence were also observed across cities, counties, and districts within the same city/province. The region with the largest within-city/province disparity ratio was Gyeonggi, at 1.76, reflecting a structure with relatively large health disparities among basic local governments within the province, while Ulsan, at 1.11, was confirmed as the region with the smallest disparity (Supplementary Figure 1; available online) [7].

Furthermore, analysis of obesity prevalence by sociodemographic characteristics using the 2024 KCHS data showed significant differences in obesity prevalence by sex, age, educational level, household type, and marital status, among other factors (p<0.05).

By sex, obesity prevalence was 41.4% among men and 23.0% among women, with the prevalence among men approximately 1.8 times higher than that among women. By age group, men in their 30s and 40s showed the highest obesity prevalence, at 53.1% and 50.3%, respectively, when socioeconomic activity is the highest. In contrast, among women, obesity prevalence gradually increased with age and reached the highest level of 27.9% among those aged 70 years or older.

Obesity prevalence showed differentiated distributions by sex according to individuals’ socioeconomic conditions. Among men, obesity prevalence was relatively higher among high-income, highly educated, and office-based occupational groups, with rates of 47.0%, 45.8%, 44.9%, and 44.5% among office workers; professional, administrative, and managerial workers; those with a college degree or higher; and those with a monthly household income of KRW 5 million or more. In contrast, obesity prevalence among women tended to be higher in low-income and manual labor groups, including 30.2%, 30.7%, and 27.8% among those working in agriculture, forestry, and fisheries; those with a middle school education or lower; and those with a monthly household income of less than KRW 2 million. By household type and marital status, men living in households with two or more members had a higher obesity prevalence, at 41.7%, than those living in single-person households, at 39.9%. Among men, obesity prevalence was 42.4% among unmarried individuals, which was higher than that among married men, at 41.8%, and those who were widowed, divorced, or separated, at 35.5%. Among women, unlike men, those living in single-person households had a higher obesity prevalence, at 23.6%, than those living in households with two or more members, at 22.9%. Among women who were widowed, divorced, or separated, obesity prevalence was 26.6%, which was higher than that among unmarried women, at 18.7%, and women with a spouse, at 23.3% (Table 1).

Table 1. The prevalence of obesity by sociodemographic characteristics, 2024 (N=229,197).

Category		Overall	Sex*
			Male	Female
Overall		32.6	41.4	23.0
Age (yr)*	19–29	28.9	39.9	16.8
	30–39	37.8	53.1	21.1
	40–49	36.1	50.3	21.4
	50–59	32.5	41.6	23.2
	60–69	30.1	34.0	26.6
	70+	27.0	26.0	27.9
Occupation	Professional/administrative	32.2	45.8	17.0
	Office work	33.3	47.0	18.5
	Sales/service	33.4	46.8	24.2
	Agriculture/fishery/forestry	34.4	36.7	30.2
	Skilled/manual labor	38.4	42.3	28.2
	Unemployed	27.5	32.6	24.4
Education level*	Middle school graduates	31.0	31.4	30.7
	High school graduates	33.0	40.4	24.7
	College graduates or higher	32.0	44.9	17.7
Monthly household income	Less than ₩2 million	29.2	31.0	27.8
	₩2–3 million	31.6	38.0	25.8
	₩3–4 million	33.9	41.8	25.2
	₩4–5 million	34.3	43.4	24.2
	More than ₩5 million	32.4	44.5	19.7
Household composition*	Single-person household	31.9	39.9	23.6
	Two or more persons	32.2	41.7	22.9
Marital status*	Never married	32.5	42.4	18.7
	Married	32.7	41.8	23.3
	Widowed, divorced, or separated	29.4	35.5	26.6

Unit: %. The prevalence of obesity by sociodemographic characteristics was calculated using crude rates based on nationally weighted averages. *p<0.05 (based on complex sample design logistic regression analysis).

Conclusion

This study analyzed the status of obesity prevalence among adults in the ROK between 2015 and 2024. Obesity prevalence among adults in the ROK increased continuously over these 10 years, reaching 34.4% in 2024. This finding indicates that approximately one in three adults had obesity and represents a sharp increase of approximately 30.8% compared with the obesity prevalence in 2015 (26.3%). In particular, obesity prevalence increased in all 17 metropolitan cities and provinces nationwide, confirming that obesity is a nationwide public health challenge extending beyond specific regions.

Differences in obesity prevalence according to sociodemographic characteristics were also identified. Among men, higher obesity prevalence was observed among highly educated, high-income, and office-based occupational groups. In contrast, among women, higher obesity prevalence was observed among low-income and manual labor groups. These findings suggest that sex is an important factor in establishing obesity management policies and show that future policies require tailored approaches reflecting the characteristics of each sex and population group. In addition, regional health disparities have also intensified, not only in terms of the difference between Jeju, which had the highest obesity prevalence at (36.8%), and Sejong, which had the lowest obesity prevalence (29.1%), but also in terms of disparities of up to twofold within the same city, county, and district, indicating the need for more comprehensive management strategies at the regional level.

One of the limitations of this study is that it used self-reported survey data. Self-reported height and weight may be subject to errors depending on respondents’ level of awareness of their health status and individual characteristics [8], and such errors have been reported to differ according to sociodemographic characteristics, such as age and sex [9]. In addition, because respondents may report the same health status differently depending on differences in health awareness and access to health information, caution is required in interpreting the results.

Nevertheless, this study is meaningful as basic evidence for the obesity surveillance system in that it presents long-term trends in obesity levels and disparities among adult population groups in the ROK based on KCHS data. Furthermore, as the obesity management environment is rapidly changing due to factors such as the recent commercialization of anti-obesity medications, future obesity policies are required to shift from a prevention-centered system to an integrated management system that includes treatment. The findings warrant a comprehensive policy design considering health insurance and health equity, together with tailored strategies reflecting population-group characteristics and sex differences.

Supplementary Materials

Supplementary data are available online.