6 Ways to Get Quality Protein on a Plant-based Diet in Japan

Get Your Protein Without Overloading on Soy

Protein is essential for repairing muscle tissue, supporting recovery, and building strength, especially after high-intensity workouts. Whether you’re weightlifting, doing cardio, or engaging in any form of intense physical activity, protein provides the building blocks your body needs to grow and recover. For those on a plant-based diet, like myself, getting sufficient protein can feel tricky—but Japan has a wide variety of options to help you hit your protein goals.

Soy products like tofu, edamame, and soy milk are common protein staples, and they’re nutritionally outstanding. Contrary to myths that soy is harmful to hormones, multiple studies (The Journal of the American College of Nutrition, 2019) show that moderate soy consumption has no adverse effects on testosterone levels and offers benefits like reducing cholesterol and inflammation. Soy products are complete proteins, meaning they contain all nine essential amino acids.

Still, it’s good to diversify your diet. Below, we’ll explore six protein-rich plant-based foods available in Japan, ranked by protein density per 100g. We'll also highlight their additional nutritional benefits and how they fit into a healthy diet.

1. Chia Seeds (チアシード) – 17g Protein per 100g

Chia seeds pack 4g of protein per 2 tablespoons (17g per 100g). In addition to protein, they’re high in omega-3 fatty acids, particularly alpha-linolenic acid (ALA), which contributes to heart and brain health. A single 28g serving provides 4,915mg of ALA, far exceeding the recommended daily intake of 1,600mg for men and 1,100mg for women (National Institutes of Health).

These tiny seeds are also rich in dietary fiber, with 10g per serving—40% of the recommended daily value—making them great for digestion and satiety. Buy 1kg Black Chia Seeds on Amazon Japan

💡 Pro Tip: Mix chia seeds with almond milk to make a pudding or sprinkle them over oatmeal and smoothie bowls for an easy nutritional boost.

2. Buckwheat (そば・蕎麦) – 13g Protein per 100g (uncooked)

Buckwheat, often used in Japanese soba noodles, contains 13g of protein per 100g uncooked. It’s also an excellent source of manganese, providing 34% of the daily recommended intake per cooked cup. Manganese plays a vital role in bone health, metabolism, and reducing oxidative stress (National Institutes of Health).

Unlike refined grains, buckwheat is gluten-free, making it a great choice for those with gluten sensitivities. Its nutty flavor works well in a variety of dishes. Buy 100% Soba Noodles on Amazon Japan

💡 Pro Tip: Try cold soba noodles topped with sesame seeds and shredded nori for a refreshing, high-protein meal.

3. Quinoa (キヌア) – 14g Protein per 100g (uncooked)

Quinoa is a standout in plant-based diets because it’s a complete protein, containing all nine essential amino acids, and provides 14g of protein per 100g uncooked. It’s particularly high in magnesium, offering 118mg per cup cooked—30% of the daily recommended intake. Magnesium supports muscle function and reduces muscle cramps, making it especially valuable for athletes.

Quinoa also contains flavonoids like quercetin and kaempferol, which have anti-inflammatory and antioxidant properties that can aid recovery post-workout (Journal of Food Science and Technology, 2015). Buy 2kg of Quinoa on Amazon Japan

💡 Pro Tip: Use quinoa as a base for veggie bowls or mix it with Japanese miso dressing for a flavorful, protein-packed salad.

4. Pumpkin Seeds (パンプキンシード) – 19g Protein per 100g

Pumpkin seeds, or "kabocha no tane," are nutritional powerhouses, offering 19g of protein per 100g and providing significant amounts of iron and zinc. A 28g serving contains 2.5mg of iron—14% of the daily recommended intake for men and 8% for women (National Institutes of Health). Iron is crucial for oxygen transport in the blood, which is key for maintaining energy during workouts.

They’re also high in magnesium, with 156mg per serving (37% of the RDI), supporting muscle recovery and bone health. Buy Raw Pumpkin Seeds on Amazon Japan

💡 Pro Tip: Roast pumpkin seeds with a pinch of salt or spices and use them as a crunchy topping for soups, salads, or rice dishes.

5. Koya Dofu (高野豆腐) – 47g Protein per 100g (rehydrated)

Koya dofu, or freeze-dried tofu, is a traditional Japanese ingredient with a protein density of 47g per 100g rehydrated. It’s also a good source of calcium, with one serving providing about 120mg—10% of the daily recommended intake. Calcium is essential for bone health and muscle contraction, especially for those engaging in weight-bearing exercises.

This shelf-stable, lightweight ingredient is ideal for meal prep and adds a chewy texture to dishes. It’s affordable and widely available in Japanese supermarkets for ¥300-¥500 per pack. Buy Koya Dofu on Amazon Japan

💡 Pro Tip: Simmer rehydrated koya dofu in a soy sauce and kombu broth for a delicious, protein-packed side dish that pairs perfectly with rice.

6. Spirulina (スピルリナ) – 57g Protein per 100g

Spirulina, a blue-green algae, is the most protein-dense option on this list, offering 57g of protein per 100g. It’s also packed with vitamin B12, a nutrient crucial for energy production and red blood cell formation. Just 1g of spirulina contains 2.4mcg of B12, meeting the daily recommended intake of 2.4mcg for adults (National Institutes of Health).

In addition, spirulina is high in antioxidants, particularly phycocyanin, which gives it its distinctive color and helps reduce inflammation and oxidative stress. Buy 500g Spirulina Powder on Amazon Japan

💡 Pro Tip: Add spirulina powder to your morning smoothie or mix it into homemade protein bars for a portable snack.

The Bottom Line

Protein is essential for muscle repair, recovery, and energy, especially for anyone engaging in high-intensity training. While soy products like tofu and edamame are fantastic and safe sources of protein, diversifying your diet ensures you get a wide range of nutrients to support your health and fitness goals.

From chia seeds to spirulina, these six protein-packed foods available in Japan offer variety, flavor, and exceptional nutrition. Incorporate them into your meals to fuel your workouts and take your performance to the next level.

💪 Ready to power up your plate? Try one or two of these options this week and feel the difference in your energy and recovery!

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