Author: Asami Goto is a bilingual Japanese food writer based in Tokyo. Photos by: Eri Nakamura is a food photographer based in Kobe.
Edited by: Matt Eisenhauer
Considering how many Japanese people eat miso soup every single day, it's safe to assume that it's good for you. Right? But there's a catch. If you're on a keto or low-carb diet, you're probably still wondering what exactly is in miso soup and if it's low-carb. I'll make the answers clear so you can decide for yourself if miso soup is right for your diet.
After answering your questions about carbs, you can also learn more about miso's nutritional content and its other health benefits. Plus, I'll share some tips on how to make miso soup lower in carbs. By the end, you should have a better idea of how to make your own version of miso soup with low-carb ingredients.
For informational purposes only-- please consult your doctor or nutritionist.
Is miso soup high in carbs?
Miso soup is not generally considered a low-carbohydrate food.
The key ingredient to make miso is soybeans. While soybeans are a rich source of protein and fiber, they also contain some carbohydrates. Miso also contains the sugar component of soybeans, which is a form of carbohydrate.
Wait. I know you might be feeling pretty discouraged right about now. The good news is that the carbohydrate content of miso soup can be relatively low when calculated per cup. Also, the amount of carbohydrates depends on the type of miso paste used as well as any additional ingredients. You can make a version of miso soup that's lower in carbs.
Considering the potential health benefits of the centuries-old fermented paste, it may just be worth the extra carbs.
Remember, the Japanese are some of the longest-living people on the planet.
How many carbs are in miso soup?
According to WebMD, a 1-cup (240-gram) serving using miso, tofu, chicken broth, seaweed or kelp, mushrooms, salted cod, and vegetable oil contains 5.45 grams of carbohydrates. Note that chicken broth and vegetable oil are not used to make traditional miso soup.
A single serving of miso soup can contain between 3 to 7 grams of net carbs.
To get more detailed information, I researched this question in Japanese.
According to Yukari, a registered dietician, the carbohydrate content of miso soup without any extra added ingredients to the broth is 5.02 g per bowl (172 g).
Miso soups with low-carb ingredients were as follows:
Wakame seaweed miso soup: 5.86 g per bowl (174g)
Shijimi clam miso soup: 5.59 g per bowl (185g)
Nameko miso soup: 6.07 g per bowl (192g).
Can you eat miso soup on a ketogenic diet?
You know it's healthy, but you're still wondering if miso soup is keto-friendly.
There's some conflicting information available on the internet. I did some research to help you make your own informed decision about whether or not miso soup suits your diet.
For the strict keto dieters, the answer is probably no. If you're limiting yourself to 20 grams of carbs per day, even one tablespoon of miso paste will take a sizable cut into your daily carb allowance.
No, a small amount of miso may not kick you out of ketosis. It may, however, make it pretty challenging to stay below your daily carb limit.
You'll have to decide if miso's health benefits are worth the 4 - 6 grams of carbs.
Miso paste - is it low carb?
It depends on the type of miso, but the short answer is no. Miso paste is not low-carb.
Yes, no doubt miso has some potential health benefits as a fermented food. It's become a staple ingredient in Japanese home cooking since it was first brought from China 1,300 years ago. But, it does have a high carbohydrate content and contains some sugar.
On average, one tablespoon of miso contains about 4 grams of carbohydrates.
I checked some nutritional facts on the back of containers of Hikari Miso, which is available overseas.
These were the amounts listed on the labels (per tablespoon):
Red Miso: 4 grams total carbohydrates / 2 grams sugar
Awase Miso: 4 grams total carbohydrates / 3 grams sugar
White Miso: 4 grams total carbohydrates / 4 grams sugar
Unless you follow a very strict keto diet, you may still want to consider adding miso to your diet. I do! I add miso to stir fries and have miso soup more than once a week.
Which type of miso is low-carb/keto?
There are three types of miso. The type is determined by which grain is paired with soybeans (rice or barley), or if it's made with pure soybeans. Hatcho miso, the type made with pure soybeans, is the lowest in carbs because no other grains are added.
Keep in mind that the portion size of miso is usually small. You may be able to incorporate the other varieties of miso into your low-carb diet. The exception is if you follow a strict keto diet.
Miso is also classified by its color and texture. Hikari Miso, which you'll find outside of Japan, exports yellow miso, saikyo (Kyoto-style white miso), white (shiro), red (aka), and awase (mixed red + white).
White miso: contains rice (large percentage)
Yellow miso: contains barley and sometimes rice (small percentage)
Red miso: contains barley or other grains (higher percentage of miso)
As a general rule, dark brown to red misos will have a lower carbohydrate content compared to lighter-colored, sweeter misos.
What is miso soup?
Miso soup is a traditional Japanese soup. It's been an important source of nutrition for Japanese people for centuries. Even today, miso soup continues to be a staple in Japanese home-style cuisine. In Japan, it's not uncommon to be served miso soup with every meal of the day.
Miso soup is prepared by boiling miso and dashi, then adding vegetables, tofu, seaweed, and other ingredients. Ingredients vary depending on the season, with leeks, green onion, wakame seaweed, and tofu being the most commonly used.
A bowl of miso soup will almost always be served alongside a traditional Japanese breakfast with foods like tamagoyaki, grilled mackerel, and pickled vegetables. At lunchtime, it will come served next to your donburi rice bowl or with your onigiri rice balls. More often than not, it's paired with a bowl of steaming hot white rice with your meal or as shime, at the end of your dinner.
Miso Soup Key Ingredients
The base of every miso soup is primarily made from a mixture of two key ingredients: miso (fermented soybean paste) and dashi (Japanese soup stock).
What is miso?
Miso is made from soybeans, sometimes mixed with grains (usually rice or barley), and koji, a type of fungus. It's fermented and aged together with salt.
What is dashi?
Dashi (sea stock 出汁) is a subtle broth that's used to make miso soup, other soup bases like for ramen, and most of the savory dishes in Japanese cooking. Kombu (edible kelp) and katsuobushi (smoky bonito fish flakes) are the two ingredients used to make the standard form of dashi stock. The high levels of glutamates in kombu and inosinate in katsuobushi give dashi its flavor-enhancing umami flavor.
Dashi broth is simply made by slowly heating kelp and bonito flakes in water to near boiling. Although it takes only a few minutes to make homemade dashi, nowadays using instant dashi (in liquid or granular form) is far more common. Understandably, making dashi from scratch every time can become tedious for busy home cooks.
Other variations of dashi are made with small dried sardines/anchovies. Vegetarians have the option of using dashi made from only kombu or shiitake mushrooms. For people with seafood allergies, dashi made from shiitake mushrooms is the safest substitute.
In Japan, dashi is even added to eggs to make dashimaki-tamago. In a Japanese restaurant or home kitchen, a spoonful of dashi is added to practically everything!
Miso Soup: Low-carb ingredients
There's a variety of different ingredients you can use to make miso soup lower in carbs. You could start with the standard combination of wakame seaweed and tofu. Thinly sliced green onions/scallions also go well with these two.
Vegetables:
Both nori seaweed (dried seaweed sheets for sushi) and aonori (dried seaweed flakes) are two more good options. All seaweed is low in carbohydrates.
You can also try low-carb vegetables like Japanese turnip leaves, cabbage, bok choy, celery, and zucchini.
Enoki, nameko, and shiitake mushrooms are all typical miso soup ingredients. Mushrooms add umami and are low in carbs.
For the adventurous eaters, you can even add some natto (fermented soybeans).
Seafood:
The leftover scraps of fish after filleting, called ara, are added to miso soup, including the bones. This way, little goes to waste. The same goes for the heads of shrimp, and crab with the legs and shell intact. These last two are easily my favorite.
Another classic variety is made with shellfish, such as asari clams, with the shells intact.
Seafood adds wonderful umami flavor without the carbs.
Meat:
Tonjiru is another classic version of miso soup, made with thin slices of pork and konnyaku (konjac). You could adapt this recipe for tonjiru.
Onsen tamago or a soft-boiled egg is another way to add extra protein.
Health Benefits of Miso Soup
Miso has supported our health since ancient times. As the Japanese proverb says, "Rather than paying a doctor, pay a miso shop."
Nutrition:
The main ingredient of miso is soybeans. In Japan, soybeans are known as the "meat of the field" because they're rich in high-quality protein.
Miso is highly nutritious. It contains a high amount of protein, dietary fiber, manganese, and vitamin K.
Miso is also an excellent source of other micronutrients including:
- copper
- zinc
- riboflavin
- phosphorus
(Dr. Axe)
Soybeans contain natural compounds called isoflavones, an antioxidant. The dashi stock, seaweed, and other vegetables in miso soup add even more antioxidants to your miso soup. (Livestrong)
Because of miso's strong flavor and high sodium content, only a small amount is used to make miso soup or to season other traditional Japanese dishes. Considering the small amount that's used to make miso soup, one serving is not a significant source of any vitamins or minerals, except sodium. (Very Well Fit)
Gut Health:
Miso contains probiotics, which may contribute to improved gut health. Probiotics or "good bacteria" are produced during the fermentation process of miso. (Web MD)
Healthier Digestive System
Eating fermented foods such as miso may improve digestion and support your immune system. (Eating Well)
Because miso is high in probiotics, it helps the body maintain healthy bacteria levels. This bacteria contributes to digestive health, reducing gas, diarrhea, bloating, and constipation. (San J)
Even More Health Benefits:
The potential therapeutic properties, including anti‐cancer, anti‐microbial, and anti‐obesity of miso, were discussed comprehensively in this article on the National Institutes of Health (NIH).
Weight Loss
If you search the internet in Japanese, you'll inevitably find information on "The Miso Soup Diet". According to registered dietician, Miwako Kojima, it's important to include three types of ingredients: protein, vegetables, and mushrooms or seaweed. Kojima says, "By skillfully combining plenty of ingredients, your intestines will be clear, your metabolism will improve, and your body will become more toned."
While you may get some inspiration by learning more about the "Miso Soup Diet", it's important to consult your doctor. If you're restricting your diet to only miso soup, your body can lack the nutrition it needs from a healthy, balanced diet.
Important note: If you need to watch your sodium intake, take thyroid medication, or have a gluten-sensitivity or soy allergy, you should avoid miso products altogether or consult your doctor first.
Where to buy miso and dashi
You may find miso paste at your local grocery store. Dashi, on the other hand, you may have to look at a Japanese or Asian supermarket.
I encourage you to look for organic miso that's non-GMO. You can also order both ingredients online if you don't live in a large city.
Learn More
How Long Does Miso Last in the Fridge? (+ storage tips)
Miso Recipes
Miso- Marinated Grilled Fish (Saikyo-yaki)
Traditional Recipe for Miso Soup (from scratch)
Easy Recipe for Miso Soup (with dashi powder)
Asami Goto Traditional Cooking Researcher(伝承料理研究家)
Asami is dedicated to sharing the unique appeal of Japan's regional cuisines with the world. She researches local ingredients, traditions, and culinary history to explore the distinct flavors of each area.
With a deep understanding of dashi and miso, Asami creates recipes that highlight their importance in Japanese cooking. She specializes in selecting the right dashi, exploring the wide variety of miso colors and flavors, and even making homemade miso. Currently, Asami is working on a cookbook featuring Japanese family recipes from Hawaii.
Eri Nakamura Kobe-Based Freelance Photographer Specializing in Culinary Art
With roots in Kyoto and training from the Japan Institute of Photography and Film, Eri has built a career capturing the beauty of food. Eri is passionate about creating images that make culinary creations shine, helping brands tell their story through stunning visuals.
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