NHIS Suggests Adjusting Obesity Criteria in Korea from BMI 25 to 27,
The National Health Insurance Service (NHIS) Research Institute has announced on the 11th that the current domestic obesity criteria, which follow the World Health Organization (WHO) Western Pacific Region standards of a Body Mass Index (BMI) of 25 or higher, should be raised to a minimum BMI of 27 to better align with Korea’s situation.
This study tracked up to 8.47 million adults who underwent general health checkups between 2002 and 2003 over 21 years, analyzing the risks of mortality and cardiovascular diseases according to their BMI. The findings were revealed at the “2024 Autumn Conference of the Korean Society for Health Education and Promotion” on November 8.
Analyzing the correlation between BMI and overall mortality showed that, regardless of excluding deaths within 1, 3, or 5 years, the lowest mortality risk was consistently observed in the BMI 25 range, forming a U-shape pattern. When excluding deaths within the first five years of observation, mortality risk was lowest at BMI 25, while it was highest below a BMI of 18.5 and above a BMI of 35. Specifically, the increase in mortality risk beyond BMI 25 was twice as large in the BMI 29 range compared to previous ranges.
The analysis of the correlation between BMI and the incidence of cardiovascular diseases (such as hypertension, diabetes, dyslipidemia, cardiovascular, and cerebrovascular diseases) showed a general increase in disease risk with higher BMI. There was no clear basis for setting 25 as the standard for obesity. The risk of developing cardiovascular disease was lowest below a BMI of 18.5 but generally increased thereafter. For instance, the risk was highest for hypertension and diabetes at a BMI of 34 (2.06 times, 2.88 times, respectively), dyslipidemia at BMI 33 (1.24 times), and cardiovascular and cerebrovascular diseases at BMI 34 (1.47 times, 1.06 times, respectively).
The increased risk of disease occurrence beyond a BMI of 25 was evident at BMI 27 for hypertension, diabetes, and dyslipidemia; at BMI 29 for cardiovascular diseases; and at BMI 31 for cerebrovascular diseases when compared to previous ranges.
Professor Oh Sang-woo from Dongguk University Ilsan Hospital noted, “Twenty years ago, the lowest mortality risk was seen at a BMI of 23. Over time, as our body shapes, lifestyles, and disease patterns have become more Westernized, the lowest mortality risk is now at a BMI of 25, although the relationship between obesity and disease remains similar to the past.” He added, “The criteria for diagnosing obesity should prioritize its relationship with diseases, using mortality data as secondary. Adjusting the current BMI standard to 27 is deemed appropriate for Koreans.”
Lee Sun-mi, head of the Health Management Research Center at NHIS, stated, “Considering the incidence and mortality risks of cardiovascular diseases among Korean adults, there is a need to raise the current obesity standard to a minimum BMI of 27. China is already applying a BMI of 28 as their obesity standard. The NHIS plans to actively promote health management initiatives focusing on the obese population, who have a higher risk of chronic diseases and mortality.”