Rising obesity in S. Korea comes amid doubts over BMI's reliability

A concerning trend in South Korea's public health profile emerged in recent data released by the Korea Disease Control and Prevention Agency, a research arm of the Health Ministry.

According to the report, made public Oct. 18, 32.5 percent of Korean adults were classified as either overweight or obese with Body Mass Index (BMI) of 25 or above in 2022, increasing by a third from a decade before when the figure stood at 24.5 percent.

Although nearly 1 in 3 South Koreans are now classified as overweight, the country still fares better than most other advanced economies.

According to a 2022 report from the Organization for Economic Co-operation and Development based on 2020 data, 37.8 percent of Korea's adult population is overweight or obese, second only to Japan's 27.2 percent.

This contrasts sharply with figures from the UK and the US, where the percentages stand at 64.2 percent and 73.1 percent, respectively.

All of which begs the question -- is BMI a reliable measure of health risks?

The widely-used metric, which calculates weight in relation to height squared, has increasingly been criticized for its potential oversimplifications and inaccuracies.

Some experts point out that BMI can be particularly misleading for people who are significantly shorter or taller than average. Moreover, its origins from the 19th century, based primarily on a narrow demographic of White, European men, have sparked debates about its relevance to different racial and ethnic groups.

Global variations in defining overweight and obesity further complicate the picture. While a BMI of 25 to 30 is typically considered overweight in Europe and the Americas, countries in the Asia-Pacific region, including Korea tend to set lower thresholds, with 23 to 24.9 being classified as overweight and 25 or above as obese.

The adjustment reportedly addresses higher risks of metabolic diseases among Asians at lower BMI levels as indicated in some studies -- the UK's National Health Service also has different BMI cut-offs for Black and Asian people -- but it nonetheless adds fuel to an ongoing debate about the index's global relevance and reliability.

In light of these concerns, some health experts advocate for alternative measures, such as waist-to-height ratio. They say this measure offers a more accurate assessment of weight-related health risks, particularly those associated with abdominal fat, which is a far stronger health risk indicator than fat in other areas of the body. As the conversation evolves, there seems to be a growing consensus that health assessments should move beyond BMI to incorporate a more holistic view of an individual's health and fitness.