Natto vs Tempeh: Are They Nutritious for Older Women?

Both natto and tempeh are nutritious for older women. They are fermented soybean foods rich in probiotics, but they differ.  

Natto vs tempeh nutrition  

Both are high in protein and fiber. Natto provides substantially more calcium, iron, and potassium.  

A three-ounce portion of tempeh provides  

  • 190 calories
  • 20 grams protein 
  • 11 grams carbs 
  • 4 grams fiber 
  • 1.5 grams saturated fat 
  • 0 mg sodium 
  • 1.5 mg iron 
  • 80 mg calcium 
  • 380 mg potassium  

A ½ cup portion of natto provides  

  • 185 calories 
  • 17 grams protein 
  • 11 grams carbs 
  • 4.5 grams fiber 
  • 1.4 grams saturated fat 
  • 6 mg sodium 
  • 7.5 mg iron 
  • 190 mg calcium 
  • 640 mg potassium 


Natto vs tempeh nutrition comparison chart with pictures of the foods

Natto vs tempeh nutrition comparison chart

Natto and tempeh are both made from soybeans. Each can help you reach your goal of eating more legumes which contribute fiber, protein, and many other nutrients from these fermented beans.   

They offer cholesterol-lowering benefits too. Since older women are more at risk of heart disease, natto provides nutrients to help with prevention.   

Because women struggle with constipation more than men, both natto and tempeh are rich in fiber and can be helpful. For a female eating 2000 calories per day, 28 grams of fiber is recommended.   

Compared to premenopausal women, older women are more likely to develop high blood pressure, osteoporosis, heart disease, and related conditions. Natto and tempeh can help to lower your risk. Since natto is more nutritionally dense, it has an edge to help you more, versus tempeh.  

What is natto?  

Natto is a Japanese food that originated thousands of years ago. These fermented soybeans are a low-cost, healthy food that can be added to various food products to flavor them, like fish, meat, rice, and veggies.   

Natto is often prepared in Japanese kitchens with seaweed, onions, and mustard and served with steamed rice.  

The food has a stringy, whitish coating, and the texture is soft, sticky, slimy and offers a strong and unmistakable flavor. Natto is generally heated but can be eaten without cooking.   

What is tempeh?  

Tempeh is a fermented food traditionally made from soybeans. It originated in Indonesia and has been produced since the 18th century.  

How is natto made?  

There are three types of natto. Itohiki natto is made by administering bacteria (Bacillus subtilis) into soybeans immersed in water and allowed to ferment for one day without added salt. The soybeans are then steamed or heated to complete the preparation.  

The other two types of natto, daitokuji and hamanatto, are made by introducing mold into the soybeans, adding salt, and allowing them to sit for four to six months before finishing.   

Making tempeh  

Tempeh is made by adding a fungus (Rhizopus) to soybeans, producing a white cake. This is due to a mold (mycelium) produced during the fermentation process.   

The tempeh reminded both of us of puffed rice or wheat that had been dried and was somewhat chewy. It tended to crumble when cutting it. Stephanie and Grace enjoyed eating this soy food.  

Some tempeh is made from nonsoy foods, including other legumes such as chickpeas, adzuki, black beans, and lentils. You may also find tempeh made from seeds such as flax and sesame. We are only referring to tempeh made with fermented soybeans.  

What does natto taste like?  

The flavor of natto was stronger, richer, and more robust than tempeh and had an earthy aroma.   

The natto we tried came frozen in individually wrapped square styrofoam containers. This packaging helps the product hold temperature while transporting, which can be helpful if you are packing it for lunch.  

Two seasoning packets came in the container, hot mustard and soy sauce. The sauces can be used to your liking and may enhance the flavor. Natto would work well with steamed rice and cooked veggies.  

What does tempeh taste like?  

The flavor of tempeh is mild with a touch of pungency and takes on the taste of what it’s cooked with.   

Stephanie cut the bean cake into small cubes and added it to brown rice and tender cooked veggies. She heated it before serving it for dinner.   

Grace cut her block into strips, seasoned it with Worcestershire sauce, and baked it in the oven. She ate the strips for snacks.   

They both found tempeh to be rather filling and needed to drink plenty of water with it.  

Does natto contain K2?  

Natto is abundant in vitamin K2 (menaquinone), which differs from K1 (phylloquinone). K1 is commonly found in dark green leafy veggies while K2 is often found in animal foods. The unique fermentation process used to make natto makes it rich in vitamin K2.   

It is believed that vitamin K1 is the vitamin that assists with blood clotting. Vitamin K2 may or may not contribute to blood clotting. Still, it does remain in your body longer. It offers many other benefits, including lowering coronary heart disease risk.   

One of those is that it contributes to bone health along with calcium and vitamin D. K2 helps to clear excess calcium out of the blood vessels and prevents it from building up in your arteries walls, lowering your risk for atherosclerosis.  

If you take blood thinners, speak with your physician before increasing your vitamin K intake with either K1 or K2.  

Does tempeh contain K2?    

Tempeh and other fermented foods like kombucha and sauerkraut contain varying levels of vitamin K2. This depends on the preparation methods used. Tempeh may have some K2, but generally less than natto.  

Is natto gluten-free?  

Natto is a gluten-free product. When purchasing, look at the label to find out if any ingredients containing gluten are included. Also, check your labels for anything you wish to add to your meal, such as soy sauce or other condiments that may contain gluten.  

For instance, one of the packages of natto that Stephanie and Grace looked at contains soy sauce, which is made with wheat. So, it would not be appropriate for you if you follow a gluten-free diet.  

Is tempeh gluten-free?  

Tempeh should be gluten-free whether it comes packaged by itself or with rice. However, it is wise to check the package label to see that it says it is gluten-free. If not, read the label to look for any traces of gluten-containing ingredients like wheat.  

Grain-free tempeh and natto  

These grain-free, budget-friendly, filling soy foods contain beneficial isoflavones for women.  

What is nattokinase?  

Nattokinase, a byproduct in the fermentation process of natto, may be advantageous for those prone to blood clots. A small study of 45 human subjects looked at three groups. The participants were either on kidney dialysis, had cardiovascular disease risk factors, or were healthy.   

All groups took two capsules of nattokinase daily for two months. The researchers found the nattokinase supplementation lowered blood clotting agents for all groups and concluded it may help those prone to blood clots.  

We are looking at nattokinase in natto as a naturally occurring byproduct of this fermented food. This happens when this food is being made and could be an advantage for your health. We are not recommending a nattokinase supplement.  

Natto versus tempeh availability  

Tempeh is easier to find at your local grocery store versus natto. Stephanie checked the international sections of five supermarkets, and Grace checked 10 Japanese restaurants. They both came up empty.  

Stephanie then went to an Asian supermarket and found natto in the frozen section. It was low cost at 1.99 for a three-portion pack. Her goal was to choose a plain version instead of pre-seasoned.    

When closely examining the label on Stephanie’s purchase, we question the amounts of sodium and potassium. We do so because soy sauce and salt are listed in the ingredients. Also, beans are known as good sources of potassium.   

The label on Grace’s purchase had amounts of nutrients listed that more closely reflected the ingredients and nutrients in the USDA FoodData Central.  

The product we looked at also contains bonito extract made from fish, so the soy sauce packet that comes with natto would not be appropriate for a vegan, but the natto is perfectly fine.   

The particular brand that Stephanie purchased also showed lower amounts of calcium and iron than what is shown in USDA’s Food Data Central.   

This is why it’s always important to check the label of your food. Even though the basic product may be the same, what a food company adds may change the nutritional contents.  


Natto and tempeh are both made from fermented soybeans. Because different fermentation methods are used, the final products vary greatly.   

Both give older women vital nutrients such as carbs, protein, fiber, potassium, calcium, and iron. Each comes at a budget-friendly price. You may need to visit a specialty store to find natto, but tempeh is available at many supermarkets.  

The taste varies from mild to strong, and you can add your favorite side dishes and seasonings to complement these foods.  

If you enjoyed our blog and would like to know more about soy, check out our other blogs. And if you want to know more about using herbs and spices, you can get our ebook while on this page.   

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Stephanie Turkel is a registered dietitian nutritionist based in Texas. She has 30 plus years of experience in the nutrition field. She now takes her gained knowledge and shares it with you to explain science articles into easy-to-understand information.

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Grace Rivers, RDN, CDCES

Grace is a registered dietitian nutritionist residing in Texas. She has over 30 years of experience in nutrition. Grace loves translating science articles into easy-to-understand information for you.


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