In a recent study published in the journal BMJ Openresearchers investigated the relationship between kimchi consumption and obesity in South Korea.
Obesity is related to dietary, environmental, and lifestyle factors and is a major risk factor for diabetes, chronic kidney disease, cardiovascular disease, and hyperlipidemia. The prevalence of obesity in South Korea has been steadily increasing over the years. Meanwhile, the prevalence of abdominal obesity has also increased over time.
The increased prevalence of obesity is associated with higher medical costs. Therefore, obesity prevention remains a public health priority. In Korea, kimchi is a traditional side dish that is low in calories but rich in vitamins, dietary fiber, polyphenols and lactic acid bacteria. There are concerns about kimchi being one of the major contributors to sodium intake.
A 2019-20 survey showed that the daily sodium intake from kimchi was 500 mg (15% of total sodium intake). Studies have shown associations between increased sodium intake and greater prevalence of hypertension and obesity. However, consumption of fermented vegetables and kimchi has been associated with lower body weight and improved total cholesterol and fasting blood glucose levels.
About the study
The present study investigated associations between kimchi consumption and obesity in South Korean adults. The researchers used data from a large, prospective, community-based cohort study, Health Examinees (HEXA). HEXA was part of a larger genomic and epidemiology study examining genetic and environmental risk factors for chronic diseases in adults aged > 40 years.
Baseline assessments in the HEXA study took place between 2004 and 2013. Participants were excluded if they had a history of cancer, cerebrovascular disease, diabetes, cardiovascular disease, hyperlipidemia, or hypertension. Those with unlikely energy intake and missing anthropometric data were also excluded.
A semiquantitative food frequency questionnaire assessed dietary intake for the previous year. Overall kimchi included kkakdugi, dongchimi (watery kimchi), baechu kimchi (cabbage kimchi) and others, e.g., mustard green kimchi, lettuce kimchi, and green onion kimchi. Intake of sodium, potassium, macronutrients and fiber was calculated. Obesity is body mass index (BMI) ≥ 25 kg/m2.
Abdominal obesity was defined as waist circumference (WC) ≥ 90 cm for men and ≥ 85 cm for women. A questionnaire was administered to collect data on sociodemographics, smoking, medical history, menopausal status, and physical activity.
Participants were divided into groups based on kimchi intake. A multivariate logistic analysis calculated odds ratios and 95% confidence intervals of obesity from kimchi intake.
Foundings
The study included 115,726 people with an average age of 51.8 years. Most participants (> 68%) were female. The prevalence of obesity was 28.2% overall, 24.7% in women and 36.1% in men. People who consumed five or more servings/day of total kimchi had increased weight and toilet compared to those who consumed less than one serving per day. they were also more likely to drink alcohol and be obese.
Men with ≥ five servings/day of total kimchi were younger, smokers, taller, and more physically active than those with less than one serving/day. In contrast, women who consumed ≥ five servings per day were older, nonsmokers, physically inactive, postmenopausal, shorter, and married compared to those who consumed less than one serving per day.
Men who consumed up to three servings of whole kimchi daily had a lower prevalence of obesity than those who consumed less than one serving per day. Baechu kimchi consumption (≥ three servings/day) among men was significantly associated with a 10% reduced prevalence of obesity and abdominal obesity relative to those with less than one serving/day.
In women, two to three servings per day of baechu consumption were associated with approximately 8% lower prevalence of obesity and 6% lower prevalence of abdominal obesity compared to those with less than one serving/day. People who consumed more than the median amount of kkakdugi were less likely to have abdominal obesity compared to non-consumers.
conclusions
Overall, the study demonstrated an inverse relationship between total kimchi consumption (one to three servings per day) and obesity risk in men. In addition, men with a higher intake of baechu kimchi had a lower prevalence of abdominal obesity and obesity. Increased kkakdugi intake was associated with lower abdominal obesity prevalence in both men and women.
While eating five or more servings of kimchi was associated with a higher prevalence of obesity, it was not statistically significant. Higher total kimchi intake was also associated with increased protein, carbohydrate, fat, sodium, cooked rice, and total energy intake. Limitations of the study include its cross-sectional design, which limits causal inference and lack of generalizability to other populations.
