A study published in the journal BMJ Open examined the relationship between kimchi consumption and obesity in South Korea.
Obesity is linked to dietary, environmental, and lifestyle factors and is a significant risk factor for diabetes, chronic kidney disease, cardiovascular disease, and hyperlipidemia. The prevalence of obesity in South Korea has steadily increased over the years. Meanwhile, the prevalence of abdominal obesity has also increased over time.
Increased obesity prevalence is associated with higher medical expenses; therefore, obesity prevention remains a public health priority. In Korea, kimchi is a traditional low-calorie side dish but rich in vitamins, fiber, polyphenols, and lactic acid bacteria. Concerns have been raised that kimchi is one of the main contributors to sodium intake.
A 2019-2020 survey found that daily sodium intake from kimchi was 500 mg (15% of total sodium intake). Studies have shown an association between increased sodium intake and a higher prevalence of hypertension and obesity. However, the consumption of fermented vegetables and kimchi has been associated with lower body weight and improved overall cholesterol and fasting blood sugar levels.
About the Study
The study examined the associations between kimchi consumption and obesity in South Korean adults. Researchers used data from a large, prospective, community-based cohort study called the „Health Examinees“ (HEXA) study. HEXA was part of a larger genome and epidemiology study that investigated genetic and environmental risk factors for chronic diseases in adults over 40 years of age.
Baseline assessments in the HEXA study were conducted between 2004 and 2013. Participants were excluded if they had a history of cancer, cerebrovascular disease, diabetes, cardiovascular disease, hyperlipidemia, or hypertension. Individuals with implausible energy intake and missing anthropometric data were also excluded.
A semi-quantitative food frequency questionnaire assessed food intake over the past year. The total kimchi included Kkakdugi, Dongchimi (watery kimchi), Baechu-Kimchi (cabbage kimchi), and others such as mustard green kimchi, lettuce kimchi, and spring onion kimchi. Sodium, potassium, macronutrient, and fiber intake were calculated. Obesity was defined as a body mass index (BMI) ≥ 25 kg/m2.
Abdominal obesity was defined as a waist circumference (WC) of ≥ 90 cm in men and ≥ 85 cm in women. Sociodemographic, smoking, medical history, menopausal status, and physical activity data were collected using a questionnaire.
Participants were divided into groups based on kimchi intake. A multivariable logistic analysis estimated the odds ratios and 95% confidence intervals for obesity following kimchi consumption.
An average of 115,726 people aged 51.8 years participated in the study. Most participants (>68%) were female. The overall obesity prevalence was 28.2%, with 24.7% in women and 36.1% in men. Individuals who consumed a total of five or more servings of kimchi per day had higher weight and waist circumference (WC) compared to those consuming less than one serving per day. They also consumed alcohol more frequently and had a higher prevalence of obesity.
Men consuming a total of five or more servings of kimchi per day were younger, smokers, taller, and more physically active than those consuming less than one serving of kimchi per day. In contrast, women consuming five or more servings per day were older, non-smokers, physically inactive, postmenopausal, shorter, and married compared to those consuming less than one serving per day.
Men who consumed up to three servings of kimchi daily had a lower prevalence of obesity compared to those consuming less than one serving per day. The consumption of Baechu-Kimchi (≥ three servings/day) was significantly associated with a 10% lower prevalence of obesity and abdominal obesity in men compared to those with less than one serving/day.
Among women, consuming two to three servings of Baechu per day was associated with approximately 8% lower prevalence of obesity and 6% lower prevalence of abdominal obesity compared to women consuming less than one serving per day. Individuals consuming Kkakdugi in greater than the median amount had a lower risk of abdominal obesity compared to non-consumers.
Overall, the study showed a reverse association between total kimchi consumption (one to three servings per day) and the risk of obesity among men. Furthermore, men with higher Baechu-Kimchi intake had a lower prevalence of abdominal obesity and obesity. Increased Kkakdugi intake was associated with the prevalence of abdominal obesity in both men and women.
While consuming five or more servings of kimchi was associated with a higher prevalence of obesity, it was not statistically significant. Higher overall kimchi intake was also associated with increased protein, carbohydrate, fat, sodium, cooked rice, and total energy intake. Study limitations include its cross-sectional design, which limits causal conclusions, and its lack of generalizability to other populations.
- Jung H., Yun Y., Hong SW, et al. (2024). Association between Kimchi Consumption and Obesity based on BMI and Abdominal Obesity in South Korean Adults: A Cross-Sectional Analysis of the Health Examinees Study. BMJ Open. doi: 10.1136/bmjopen-2023-076650. https://bmjopen.bmj.com/content/14/2/e076650