Moderate kimchi intake linked to lower obesity rates, study shows

By Tarun Sai LomteReviewed by Sophia CoveneyFeb 4 2024

In a recent study published in the journal BMJ Open, researchers explored 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 increased steadily over the years. Meanwhile, the prevalence of abdominal obesity has also increased over time.

Increased obesity prevalence is associated with higher medical expenditure; thus, obesity prevention remains a public health priority. In Korea, kimchi is a traditional side dish low in calories but rich in vitamins, dietary fiber, polyphenols, and lactic acid bacteria. There are concerns about kimchi as one of the major contributors to sodium intake.

A 2019-20 survey revealed that daily sodium intake from kimchi was 500 mg (15% of total sodium intake). Studies have shown associations between increased sodium intake and a greater prevalence of hypertension and obesity. Nevertheless, consuming 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 explored the 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 genome and epidemiology study examining genetic and environmental risk factors for chronic diseases in adults aged > 40.

Baseline assessments in the HEXA study were performed between 2004 and 2013. Participants were excluded if they had a history of cancer, cerebrovascular disease, diabetes, cardiovascular disease, hyperlipidemia, or hypertension. Those with an implausible energy intake and missing anthropometric data were also excluded.

A semi-quantitative food frequency questionnaire assessed dietary intake for the past year. Total 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 having a body mass index (BMI) ≥ 25 kg/m².

Abdominal obesity was defined as having a waist circumference (WC) ≥ 90 cm for males and ≥ 85 cm for females. A questionnaire was administered to capture data on sociodemographics, smoking, disease history, menopause status, and physical activity.

Participants were stratified into groups based on kimchi intake. A multivariable logistic analysis estimated odds ratios and 95% confidence intervals of obesity by kimchi intake.

Findings

The study included 115,726 individuals aged 51.8, on average. Most participants (> 68%) were female. Obesity prevalence was 28.2% overall, 24.7% in females, and 36.1% in males. Individuals consuming five or more servings/day of total kimchi had increased weight and WC compared to those consuming less than one serving per day; they were also more likely to consume alcohol and be obese.

Males with ≥ five servings/day of total kimchi were younger, smokers, taller, and more physically active than those with less than one serving/day. By contrast, females consuming ≥ five servings per day were older, non-smokers, physically inactive, post-menopausal, shorter, and married compared to those consuming less than one serving a day.

Males consuming up to three servings of total kimchi daily had a lower obesity prevalence than those consuming less than one serving a day. Baechu kimchi consumption (≥ three servings/day) among males was significantly associated with a 10% reduced prevalence of obesity and abdominal obesity relative to those with less than one serving/day.

In females, two to three servings per day of baechu consumption was associated with about 8% lower obesity prevalence and 6% lower prevalence of abdominal obesity compared to those with less than one serving/day. Individuals consuming kkakdugi more than the median quantity had lower odds of having abdominal obesity compared to non-consumers.

Conclusions

Overall, the study illustrated an inverse association between total kimchi consumption (one to three servings per day) and obesity risk in males. In addition, males 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 males and females.

While consuming five or more servings of kimchi was associated with higher obesity prevalence, it was not statistically significant. Higher total kimchi intake was also associated with increased protein, carbohydrates, fat, sodium, cooked rice, and total energy intake. The study’s limitations include its cross-sectional design, which limits causal inference, and lack of generalizability to other populations.