Nearly half of young Korean men are now classified as obese based on the body mass index, and roughly one in three has prediabetes or prehypertension, according to a new study.
The study, led by professors Lee Yong-ho and Kim Seung-hee of Wonkwang University Sanbon Hospital, analyzed health data from 3,609 South Korean nationals aged 19 to 39 between 2019 and 2021. Their findings, published in the Korean Journal of Family Practice last December, reveal that obesity in this age group is strongly tied to stress, education levels, income, and lifestyle habits -- with key differences between men and women.
Beyond some US studies that show obesity to be correlated with inactivity, this study specifically suggests that socioeconomic pressures and psychological stress are major drivers of weight gain in Korea.
Young Koreans are gaining weight
In this study, obesity is defined using the BMI, classifying individuals with a body mass index of 25 or higher as obese, a stricter threshold than the 30 used in the US and Europe. This index also has major limitations, for instance, it doesn’t differentiate between fat and muscle. Thus, some people with high muscle mass may be misclassified as obese, while others with a normal BMI but with high body fat (known as normal-weight obesity) may still face serious health risks.
To get a clearer picture of metabolic health, the researchers also looked at blood sugar, cholesterol, blood pressure and liver enzyme levels -- and the results were alarming.
First, obesity in Korea is increasing at an increasingly higher rate among young adults in general. Compared to 2009, when 32.2 percent of Koreans in their 30s were obese, that number has jumped to 39.6 percent percent in 2019.
Among men in the study, 45.4 percent were classified as obese, and nearly a third had conditions of prediabetes (29.2 percent) and prehypertension (31.1 percent) -- early indicators of diabetes and heart disease.
For women, obesity rates were lower at 20.5 percent, and fewer had conditions of prediabetes (17.7 percent) or prehypertension (12.5 percent). However, women’s risk of obesity was more closely linked to unemployment and economic hardship, while men’s risk factors were cited as drinking, smoking history and being married.
What's driving the rising obesity rates?
The study found that stress is one of the biggest drivers of obesity in both men and women. High stress levels can disrupt metabolism, increase fat storage and lead to unhealthy eating and sleeping patterns.
Socioeconomic factors also play a major role. Lower education levels were linked to higher obesity rates, possibly due to lack of health awareness or fewer opportunities for exercise and healthy eating. Among men, lower income levels were a major predictor of obesity, while women who were unemployed or in physically demanding jobs were at higher risk.
Lifestyle habits also matter. Men who drank alcohol frequently were more likely to be obese, while for women, the opposite was true -- those who drank were actually less likely to be obese. The researchers noted that this could be linked to lifestyle differences, with men engaging in high-calorie social drinking while women who drink may lead more active social lives.
Surprisingly, physical activity had no clear link to obesity in this study. Researchers suggest this could be due to reverse causality -- meaning that obese individuals may exercise more to lose weight, rather than inactivity being the initial cause of obesity.
The study does not explicitly explain why young Korean men measure up less healthy than their female counterparts. While it identifies lifestyle risk factors, such as higher alcohol consumption (72.9 vs. 61.0 percent), smoking (33.1 vs. 9.0 percent) and calorie intake (2,405 vs. 1,717 kcal/day), it does not analyze how these directly contribute to worse metabolic health.
mjh@heraldcorp.com
