Study finds that moderate intake of kimchi is associated with lower obesity rates

In a recent study published in the journal BMJ OpenResearchers investigated the relationship between kimchi consumption and obesity in South Korea.

Obesity is associated with nutritional, environmental, and lifestyle factors and is a significant risk factor for diabetes, chronic kidney disease, cardiovascular disease, and hyperlipidemia. Obesity prevalence in South Korea has steadily increased over the years. On the other hand, the prevalence of abdominal obesity is also increasing over time.

Increased obesity prevalence is associated with increased health care 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 is concern that kimchi is one of the main causes of salt intake.

A 2019-20 study found that daily sodium intake from kimchi was 500mg (15% of total sodium intake). Studies have shown an association between increased sodium intake and increased prevalence of hypertension and obesity. Nevertheless, consuming fermented vegetables and kimchi has been shown to reduce weight and improve total cholesterol and fasting blood sugar levels.

About research

This study investigated the association between kimchi intake and obesity among Korean adults. The researchers used data from a large, prospective, community-based cohort study, Health Examination (HEXA). HEXA was part of a larger genomic and epidemiological study investigating genetic and environmental risk factors for chronic disease in adults aged 40 and older.

The baseline assessment of the HEXA study was conducted between 2004 and 2013. Participants with a history of cancer, cerebrovascular disease, diabetes, cardiovascular disease, hyperlipidemia, or hypertension were excluded. Those with implausible energy intake or missing anthropometric data were also excluded.

Food intake over the past year was assessed using a semi-quantitative food frequency questionnaire. Kimchi included kakdugi, donchimi (watery kimchi), baechu kimchi (cabbage kimchi), and others such as mustard green kimchi, lettuce kimchi, and green onion kimchi. Intakes of sodium, potassium, macronutrients, and fiber were calculated. Obesity refers to a body mass index (BMI) of 25 kg/m or higher.².

Abdominal obesity was defined as waist circumference (WC) ≥90 cm in men and ≥85 cm in women. A questionnaire was administered to collect data on sociodemographics, smoking, medical history, menopausal status, and physical activity.

Participants were stratified into groups based on kimchi intake. Multivariate logistic analysis estimated odds ratios and 95% confidence intervals for obesity associated with kimchi consumption.

Investigation result

The study involved 115,726 people with an average age of 51.8 years. Most participants (>68%) were female. Obesity prevalence was 28.2% overall, 24.7% in women, and 36.1% in men. People who ate five or more servings of kimchi a day had increased body weight and toilet use compared to those who consumed less than one serving a day. They were also more likely to consume alcohol and be obese.

Men who consumed five or more servings of kimchi per day were younger, smokers, taller, and more physically active than men who consumed less than one serving per day. In contrast, women who consumed five or more servings per day were older, non-smokers, less physically active, postmenopausal, shorter, and married than women who consumed less than one serving per day.

Men who consumed up to three total servings of kimchi per day had lower obesity rates than men who consumed less than one serving of kimchi per day. Men's baechu kimchi intake (3 or more servings per day) was significantly associated with a 10% lower prevalence of obesity and abdominal obesity compared to men who consumed less than 1 serving per day.

Among women, consuming pethu two to three times a day was associated with an approximately 8% lower prevalence of obesity and a 6% lower prevalence of abdominal obesity than those who consumed pethu less than once a day. People who consumed more than the median amount of kaktugi were less likely to develop abdominal obesity than non-consumers.

conclusion

Overall, this study showed an inverse association between total kimchi intake (1 to 3 servings per day) and obesity risk in men. In addition, men with higher intakes of baechu kimchi had lower prevalence of abdominal obesity and obesity. Increased intake of kakdugi was associated with the prevalence of lower abdominal obesity in both men and women.

Eating more than 5 servings of kimchi was associated with higher obesity rates, but this was not statistically significant. Higher total kimchi intake was also associated with higher protein, carbohydrate, fat, sodium, cooked rice, and total energy intake. Limitations of this study include the cross-sectional design, which limits causal inferences, and the lack of generalizability to other populations.