The Habit from Japan That Danes Dropped — and Why We Feel It Now

There is one daily habit from Japan that was once completely natural in Denmark as well — but which quietly disappeared over the last 40 years. This simple morning tradition today is linked to Japan’s status as one of the world’s longest-living countries, while Danes experience increasing fatigue, constipation, and lack of energy. Let’s look at what we dropped — and why it makes a measurable difference.

What is the Japanese habit that Danes abandoned?

The Japanese habit is about starting the day with fermented foods and plant-rich meals — especially seaweed, vegetables, algae, and fermented ingredients like miso, kimchi, natto, and spirulina. In Japan, breakfast is traditionally composed of seaweed, pickled vegetables, algae products, and fermented sauces. These foods benefit digestion and gut flora, provide fiber, and contribute to a feeling of well-being throughout the day.

In Denmark, it was once common to eat rye bread, fermented dairy products, pickled vegetables, and oatmeal for breakfast. But gradually, we switched to white bread, sweet cereals, croissants, and industrially processed breakfast foods. With that, an important source of fiber, probiotics, and support for digestion and gut flora disappeared. The result? More Danes report fatigue, bloating, constipation, and lack of energy — symptoms that Japanese people experience much less frequently.

The difference between Danish and Japanese breakfast today

Where a typical Danish breakfast today often consists of yogurt with sugar, toast with cold cuts, or a croissant with coffee, the classic Japanese breakfast includes:

• Miso soup with seaweed and tofu
• Grilled fish or eggs
• Fermented soy (natto)
• Rice with seaweed (nori)
• Pickled or steamed vegetables
• Green tea

It is no coincidence that Japan has one of the world's highest life expectancies and lowest rates of lifestyle diseases. Diet — especially breakfast — plays a crucial role.

Why do Danes feel this way now?

As the Danish diet has become more industrialized, we have lost key nutrients, fiber, and probiotic bacteria. This has consequences, as seen in national health data:

Fiber intake has dropped dramatically. Danes consume on average only 18-20 grams of fiber daily, while the recommendation is a minimum of 25-35 grams. In Japan, intake typically ranges from 25-30 grams, mainly from seaweed, vegetables, algae, and fermented soy products.

Microbiome diversity is reduced. A study from Stanford University showed that regular consumption of fermented foods can increase diversity in the gut microbiome — exactly what the Japanese breakfast provides and what the modern Danish breakfast lacks.

Fatigue and lack of energy are widespread. Many Danes experience fatigue already in the morning. Vitamin C helps reduce tiredness and exhaustion (1), but without sufficient intake of vegetables, fiber, and micronutrients, it is difficult to maintain energy levels.

What is spirulina, and why is it a key element in the Japanese diet?

Spirulina is a blue-green algae that has been part of the Japanese and Asian diet for hundreds of years. It contains protein, iron, B vitamins, chlorophyll, and antioxidants — and plays a central role in many studies linking algae diets to longevity and better energy.

Spirulina can help you feel more energetic (2) and support your vitality (3). Spirulina also has significant antioxidant properties (4), which can be relevant for both active people and those who experience fatigue in daily life.

Spirulina provides exactly what many Danes lack: plant-based protein, iron, vitamins — and support for energy and well-being.

How does the Japanese diet support digestion and gut flora?

One of the most underestimated factors in the Japanese diet is the close connection between fermented foods, fiber, and digestion and gut flora. The Stanford study showed that participants who increased their intake of fermented foods experienced greater microbiome diversity.

This is relevant because the state of the microbiome is linked to:

• Improved digestion and reduced bloating
• Reduced risk of constipation
• Strengthened immune system
• Better mood and mental clarity
• Lower incidence of chronic diseases

The Japanese breakfast provides probiotics (from fermented foods), prebiotics (from fiber in vegetables and seaweed), and micronutrients that support digestion and gut flora on multiple levels simultaneously.

Diet and GLP-1: What about those taking weight loss medication?

For Danes taking GLP-1-based medications like Ozempic, Wegovy, or Saxenda, fiber and plant-rich foods are particularly important. Research shows that GLP-1 treatment often causes constipation, bloating, and stomach discomfort — side effects that can be prevented or reduced with increased fiber intake and probiotics.

Research emphasizes that optimized nutrition during GLP-1 treatment not only reduces side effects but also improves long-term weight control, energy, and metabolic health.

The Japanese approach — with fiber, fermented foods, and algae — is therefore especially relevant for Danes who take medication but experience digestive problems or fatigue.

How can Danes reintroduce the Japanese habit?

You don’t need to make miso soup every morning to benefit from the Japanese approach. Here are simple, practical ways to reintroduce the habit:

1. Start the day with fiber and greens

Replace sweet cereals with oatmeal topped with seeds, berries, and spirulina. Or mix a greens powder into water or a smoothie — it gives you fiber, vitamins, and chlorophyll in under 30 seconds.

2. Add fermented foods

Eat yogurt (natural, unsweetened), kefir, kimchi, sauerkraut, or kombucha daily. Even small amounts make a difference for the microbiome.

3. Drink green tea instead of coffee

Green tea contains antioxidants, L-theanine, and moderate caffeine — without the energy crashes that coffee often causes.

4. Eat more vegetables for breakfast

Add spinach, avocado, cucumber, or tomato to your breakfast. It may sound unconventional, but it provides fiber, vitamins, and a feeling of fullness that lasts longer than white bread.

5. Use spirulina or greens powder

If you don’t like seaweed or algae, a greens powder with spirulina, chlorophyll, and fiber can be an effective substitute. It gives you plant-based nutrients without having to change your entire breakfast.

Frequently Asked Questions

What is the Japanese habit that Danes dropped?

The Japanese habit is about starting the day with plant-rich, fiber-rich, and fermented foods — such as seaweed, vegetables, algae, and miso. Previously, Danes ate rye bread, oatmeal, and pickled vegetables for breakfast, but today sugary, industrially processed products have become the norm.

Why does Japan have a higher life expectancy than Denmark?

Japan has the world's second-highest average life expectancy, which is partly attributed to a diet rich in fiber, fish, vegetables, seaweed, algae, and fermented foods. Studies indicate that this diet benefits digestion and gut flora and provides essential nutrients that protect against lifestyle diseases.

Can spirulina reduce fatigue?

Spirulina can help reduce fatigue (5) and support your vitality (6). Spirulina contains B vitamins, iron, protein, and antioxidants that support energy production.

Do fibers help with constipation and bloating?

Yes. Fiber increases stool volume, promotes regular bowel function, and supports the growth of beneficial gut bacteria. For people taking GLP-1 medication, research shows that increased fiber intake can reduce constipation and bloating.

How do fermented foods support digestion and gut flora?

Fermented foods like miso, kimchi, yogurt, and kombucha contain live probiotic bacteria that increase the diversity of the gut microbiome. The Stanford study showed that regular consumption of fermented foods improves microbiome diversity.

Can I benefit from the Japanese breakfast without eating seaweed?

Yes. You can get many of the same benefits by increasing your intake of fiber, fermented foods, and plant-based nutrients. A greens powder with spirulina, chlorophyll, and fiber can provide you with plant-rich micronutrients without having to change your entire breakfast.

Conclusion: Small changes, big difference

The Japanese habit — starting the day plant-rich, fiber-rich, and fermented — is not a trend. It is a practical approach to nutrition linked to longevity, better energy, healthier digestion, and lower incidence of fatigue. We quietly dropped it in Denmark, but the consequences are clear: more people experience tiredness, bloating, constipation, and lack of energy.

You don’t need to move to Japan. You just need to reintroduce the habit — by eating more fiber, adding vegetables or seaweed to breakfast, choosing fermented foods, and prioritizing nutrients over convenience.

Dietary supplements should not replace a varied diet and healthy lifestyle. Consult a doctor or healthcare professional if you are pregnant, breastfeeding, taking medication, or have a chronic condition.