Eating Kimchi for Weight Loss: Could it Actually Work?
Key Takeaways:
Kimchi refers to a specific fermentation technique where vegetables are brined and then fermented with various supplemental ingredients, such as garlic and sugar.
Eating kimchi is believed to promote weight loss as it’s rich in dietary fiber and probiotics (specifically, lactic acid bacteria strains).
While some studies have shown an association between kimchi consumption, weight loss, and an improvement in blood glucose levels, the evidence isn’t convincing.
You can still enjoy kimchi as part of a healthy, varied, balanced diet. Just be mindful of your total daily sodium intake.
Ultimately, the most effective way to lose weight is by adopting a healthy lifestyle, such as eating a well-balanced, nutritious diet and staying physically active.
Divine over a bed of steaming hot rice. Folded into custardy-soft scrambled eggs. Sandwiched between crunchy lettuce and grilled pork belly. Or, frankly, even just as it is.
But if you thought kimchi’s incredibly layered and appetite-whetting flavor profile (a drool-worthy, harmonious blend of tangy, spicy, and umami) was all it had to offer, well. You might be in for a pleasant surprise.
Because apparently, there’s evidence that eating kimchi for weight loss could work.
What is kimchi?
First, let’s catch up. While most people’s imagery of kimchi is a singular Korean red-hot, fermented napa cabbage dish, “kimchi” is more of a verb.
It refers to a specific fermentation technique which involves:
Brining vegetables (any vegetable, but more commonly, radishes, scallions, and cucumbers) in salt or saltwater
Marinating the brined vegetables with a variety of supplemental ingredients, such as garlic, ginger, fish sauce, sugar, and gochugaru (Korean chili)
Fermenting the mixture in an air-tight container for either one to two days at room temperature or three to four days in the refrigerator to foster the growth of lactic acid bacteria strains naturally present in the ingredients (e.g., Weisella and Lactobacillus)
Skipping the fermentation step gives you “fresh kimchi”, which, although an oxymoronic expression — since you can’t technically have kimchi without fermentation — is still widely accepted and used.
Why would eating kimchi work for weight loss?
Theoretically speaking, kimchi brings two weight-loss-promoting attributes to the table.
Dietary fiber
Kimchi is made from vegetables. This means it’s packed with dietary fiber.
This known natural appetite suppressant slows gut emptying and orchestrates the release of the same hormone that GLP-1 RA weight loss drugs tap into (i.e., glucagon-like peptide 1).
Many studies have linked the intake of fiber-rich foods with a favorable impact on body weight.
This 2019 study published in The Journal of Nutrition, for example, found that dietary fiber intake, independently of macronutrient and caloric intake, promotes weight loss in adults with overweight or obesity consuming a calorie-restricted diet.
Probiotics
Alive. Thanks to the fermentation process, that’s what kimchi is.
OK, more specifically, kimchi is brimming with lactic acid bacteria, of which many strains have a well-established role as probiotics.
For the uninitiated, probiotics are live microorganisms that are good for you, especially your digestive system. You can think of them as “good” gut bacteria.
And just like dietary fiber, probiotics may support weight loss.
A 2013 study published in The British Journal of Nutrition found that women who took a strain of probiotics known as Lactobacillus rhamnosus (LGG) for 24 weeks lost more weight (about 1.8 kg) than those in the placebo arm.
Are there studies directly linking kimchi and weight loss?
Yes, there are. A handful:
2011 study published in Nutrition Research: The researchers randomly assigned 22 participants with body mass indexes (BMI) above 25 kg/m² (i.e., classified as “overweight” and “obese”) to two 4-week diet phases separated by a 2-week washout period. During each diet phase, the participants consumed 300 grams of fresh or fermented kimchi daily. At the end of the study, the researchers found that while both fresh and fermented kimchi led to a significant decrease in body weight, the latter led to a greater reduction than the latter (which makes sense since fermented kimchi offers an additional weight loss promoting feature: probiotics).
2024 study published in BMJ Open: After analyzing the data of 115,726 participants aged 40 to 69 years enrolled in the Health Examinees study in Korea, the researchers found a J-shaped association between kimchi consumption and obesity prevalence. To expand on that:
Eating one to three servings* of any type of kimchi daily was associated with a lower risk of obesity in men
Women who ate two to three servings of baechu (cabbage kimchi) were less likely to have obesity and abdominal obesity
However, individuals who ate five or more servings of any type of kimchi weighed more, had larger waist sizes, and were more likely to be obese
*Note: the serving size depends on the kimchi type (e.g., the researchers defined one serving of baechu kimchi as 50 grams and one serving of nabak kimchi as 95 grams).
You may be doing fist pumps right now if you're a kimchi lover. Because it seems like, as long as you enjoy the perfectly spicy-tart dish in moderation, you could expect it to benefit weight management … right? Mmm.
Unfortunately, the evidence isn’t convincing
Let’s pick apart the two studies individually, starting with the 2011 study.
Remember how fresh and fermented kimchi led to a “significant decrease in body weight”? Here’s what that looks like, quantified:
Fresh kimchi: 72.9 ± 9.6 (initial weight) versus 71.7 ± 9.4 (final weight)
Fermented kimchi: 73 ± 10.1 versus 71.5 ± 9.7
Sure, the difference is statistically significant, but is it practically significant (i.e., large enough to be meaningful in real life)? The answer is clear, given that the benchmark for clinically meaningful weight loss currently stands at a minimum of 5% reduction in body weight. No.
Now, what about the 2024 study?
With such a large sample size (115,726 individuals!), its findings must be credible, or at least more credible than the 2011 study, right?
Aside from its glaring shortfall of being an observational study — this means it cannot demonstrate causality, i.e., that kimchi causes weight loss — it also suffers from a deathly limitation. Potential bias.
Look at the funding source: World Institute of Kimchi.
If that hasn’t shot your eyebrows up, perhaps this would: apparently, two out of four of the paper’s authors are employed at the World Institute of Kimchi.
What about eating kimchi for diabetes?
OK, so there’s no real evidence supporting the benefits of kimchi for weight loss.
But what about diabetes? The researchers who conducted the 2011 fresh vs. fermented kimchi study actually came up with a 2013 follow-up study (published in the Annals of Nutrition & Metabolism).
This time, they recruited 21 participants with prediabetes and had them consume either fresh or fermented kimchi for the first eight weeks. After a 4-week washout period, they switched to the other type of kimchi for the next eight weeks.
Guess what the researchers found?
Fermented kimchi decreased the participants’ insulin resistance and increased insulin sensitivity.
Another 2013 RCT published in the Journal of Medicinal Food reported similar findings. In this study, the researchers randomly assigned 100 participants to two dietary groups, where they were provided with identical meals except for the amount of kimchi provided:
Low kimchi dietary intake: 15 grams daily
High kimchi dietary intake: 210 grams daily
After seven days, compared to the low kimchi intake group, those in the high kimchi intake group experienced a significant reduction in fasting blood glucose levels.
Amazing. So, does this mean kimchi definitely has beneficial effects on blood sugar control?
Not particularly:
2013 follow-up study: The researchers quantified neither the participants’ reduction in insulin resistance nor their improvements in insulin sensitivity (or, if they did, the information isn’t publicly available) — in other words, we have no idea if the effect is practically significant.
2013 RCT: Here are the changes in the participants’ blood glucose concentrations:
Low group: 78.7 ± 4.6 (pre) versus 76.5 ± 4.9 (post) mg/dL
High group: 80.7 ± 5.4 versus 75.1 ± 6.0 (post) mg/dL
The optimal fasting blood glucose level ranges from 60 to 90 mg/dL. The participants were already within optimal range; to put it bluntly, the study didn’t provide anything worth paying attention to.
What should I do?
Although kimchi is high in fiber and a good source of probiotics, ultimately, the evidence is very weak to support or recommend eating kimchi for weight loss or blood sugar control. That said, this piquant, traditional Korean dish can still be a part of a healthy, varied, and balanced diet, particularly if you enjoy it.
Just keep a careful eye on your total daily sodium intake.
A 100 gram of kimchi could contain a whopping 341 mg of sodium (although this may vary based on several factors, including preparation method and kimchi brand). The World Health Organization (WHO) recommends a daily sodium intake limit of 2,000 mg.
Eating too much sodium increases your risk of cardiovascular diseases, gastric cancer, osteoporosis, and kidney disease.
Adopt an all-rounded approach for sustainable weight loss
At the end of the day, the most effective way to lose weight is through a combination of lifestyle factors, including:
Eating a well-balanced, nutritious diet focused on an adequate amount of lean-body-mass-preserving protein and achieving calorie restriction
Being physically active (ideally, a mix of cardio and strength training)
But as you may be familiar, knowing what it takes to lose weight is wildly different from actually doing what it takes — especially when you have a punishing schedule with little breathing space, unique dietary restrictions or preferences, or just … don’t know how to begin.
NOVI Optimum can help. Combining the power of personalized nutrition and fitness plans, our health-coach-led and dietitian-monitored weight loss program may just be what you need to finally get fitter, plus shed the weight and keep it off long-term.