🔖 7 min read

I’m no biohacker, but I have a profound interest in nutrition, food, and how we can optimize our health and well-being. So of course, I always read and watch a lot of videos on new research surrounding healthy diets like the ketogenic dietintermittent fasting, paleo, and anything else that claims to be the key to optimizing our health.

Most recently, I tried intermittent fasting for 7 days. To be fair, I’m no licensed nutritionist and my diet was developed over my own research online. Here are some details on how I pursued it.

Japanese Rule to a Healthy Diet

My Attempt at Intermittent Fasting

When I Ate

There are multiple ways to intermittent fast, and multiple levels of strictness and control, but basically, I just skipped breakfast and dessert for a week, ate an early dinner, and focused on eating whole foods.

What I Ate

  • While I mainly focused on the time frame of when I was eating, rather than what I was eating, I was still careful to incorporate lots of vegetables and protein to maximize “fullness” without overeating.
  • Typical meal: Broccoli (boiled), 3 eggs, pan-roasted edamame with chilli garlic and cumin, bread, hummus, and an apple, with lots of water.

What Happened

First 24 Hours

I feel great! A little hungry before going to bed, but that’s probably because I don’t have dessert sitting in my stomach (I was used to treating myself to half a bar of dark chocolate, 250g, or recently, a piece of pineapple cake that my little sister sent me from Taiwan).

72 Hours

I am finding that I am SCARFING down all of my meals because I am so hungry. I would feel incredibly full after lunch or dinner, but find myself really hungry again after an hour. I consider that I am not eating enough calorie-dense foods. Will add more bread and butter to my meals. Generally, I feel pretty good about what I’m doing and can see myself continuing this long run with a few adjustments.

5 Days

I am still hungry all of the time, even after adding more calorie-dense foods to my meals. I have a constant headache, feel groggy, and emotionally don’t feel so good. I will go from feeling great to feeling really low and am looking forward to the end of the week. I also find myself constantly thinking about food, even while I’m eating.

7 Days

Let this end.

My Conclusion

The verdict? It doesn’t work and I absolutely hate it.

I am no expert or scientist and I am just an amateur when it comes to food nutrition, so maybe I didn’t do this diet perfectly as prescribed. But if you’re experiencing these signs, I’m thinking this diet is not sustainable in the long run.

  • Headaches
  • Negative emotions
  • Fatigue
  • Grogginess
  • Thinking about food all of the time

In addition to intermittent fasting, I’ve also tried other popular healthy diet prescriptions with mixed results, with none of them being long-lasting or sustainable.

Healthy Diet: So what is the correct way to eat?

How do we take control of our diet and optimize our health and well-being for the long run? For years, I’ve been following a single rule that has been a staple value in my house that I have found is the only one that works for me. It’s not intermittent fasting, it’s not keto, and it’s not paleo. Not only has my single rule helped me lose weight, but it’s improved my mood, energy, and overall well-being. It’s something my mother had taught me, and the whole of Japan knows about it too. It’s called: Harahachi-bunme

What is Harahachi-bunme?

Basically, if you tell any Japanese person that this is a kind of diet, they’ll look at you in a very confused way, and correct you that it’s not really. It’s a long-standing Japanese saying that directly translates to “8/10ths your stomach”; meaning, you should only eat until you are 80% full.

It follows very simple principles that we should not overindulge in food, and we should be modest about how much we eat. Neither starving nor stuffing ourselves, it follows the principle that extreme lifestyles are neither good for us nor sustainable, and the key is finding balance and middle ground to satisfy our needs.

It’s a way of looking at food and hunger in an intuitive way, with a focus on nourishment and health rather than results like weight loss or physical benchmarks. These benchmarks tend to come naturally over time anyway because when you practice neither over-indulgent eating nor deprivation, your body will respond in a sustainable manner that will last you the rest of your life. You must trust that your body knows what it needs.

How to practice Harahachi-bunme

Basic guidelines behind the principle

Eat when you are hungry

For some days this means eating two meals. For other days, it means eating four. Days following an intense day of exercise may mean you eat breakfast, lunch, dinner, dessert, and snacks in-between. For a day of travel and lots of idle sitting, it could mean just one large meal and many snacks throughout the day.

Eat whole, nutrient-dense foods

  • While not strictly in the saying, harahachi-bunme only works when you are eating healthy, nutrient-dense foods. Your body cannot accurately measure nourishment and hunger when you are consuming mostly empty calories from highly-processed foods. These empty calories lead to overeating because you are never able to reach the point of “80% full”. Focus on fruits, vegetables, proteins, and whole grains, and your stomach and brain will respond accordingly to your needs.
  • By focusing on these kinds of foods, you will not only stop hunger pangs, but you will also lose the desire to mindlessly eat. Preventing overindulgence will not be a test of willpower, but will become a natural response.

Don’t worry about counting or measuring things — your body will know

  • Just eat fruits, vegetables, proteins, and whole grains.
  • Is it really that simple? Shouldn’t you think about the composition of your macros? How about how these foods are cooked? Should it be raw or boiled or baked or pan-fried? This over-excessive thinking is what leads to extreme diets. Our bodies are thoughtful and well-run machines, and there is no need to obsessively consider these details. Trust your body, it will respond appropriately.
  • Tracking micro details won’t really be sustainable in the long-run unless you really enjoy dedicating mental energy to thinking about food in this sort of manner (and some people do!). For most of us though, just focus on consuming whole foods, limit your refined carbs, and your body will know the rest.

Stop when you’re 80% full

  • This is the most important part, as it guarantees how we develop a positive and sustainable relationship with food.
  • There are no concrete rules to how you will know when you’re 80% full, but as a guideline, I like to eat slowly and wait at least 30 minutes after eating a full meal to determine how I feel. Everyone has different lifestyles and body compositions, so it may be difficult to determine what this looks and feels like at first. But be patient, feel in tune with what your body is telling you, and if it’s signalling hunger, eat. If it’s telling you nothing, don’t eat.

Get food off your mind

  • As you practice harahachi-bunme, the idea of food should fall to the back of your mind. Stop obsessing over it, and think of it as another part of enjoying a fulfilling life. Food should be a part of what makes life interesting and enjoyable, but should not be the focus. This practice is the most difficult part to attain, and it is the part that will take the most time, particularly if you’ve had a problematic or complicated relationship with food in the past. But once you reach a point where it can fall back in your mind and take a backseat, your mental energy can be reallocated and opened to many more interesting life experiences and ideas that aren’t related to diet.

A Perspective of Nourishment & Sustenance

With this perspective shift and change in relationship with food, living will not be about eating, but eating will become the fuel and sustenance for a fulfilling lifestyle, focused on your family, friends, career, and success.

Harahachi-bunme is not really a diet, and to be honest, it’s not even really a rule. It’s a way of intuitive eating and understanding food from a perspective of nourishment and sustenance.

I’ve gone from both ends of the extreme eating spectrum and found that I was neither happy nor productive in either state. Moderation can be a lot more difficult than said, but once you master the art of it, your brain capacity really does open up for better things.

So get in touch with your thoughts, and get in touch with your body. Love it, nourish it, and treasure it. You will feel physically better, emotionally happier, and psychologically more engaged with your work and the people around you.

Kaki Omura from Kakikata Space

Get to know Kaki Okumura

I’m Japanese but was born in Dallas, Texas. Shortly after, I moved to New York where I spent a few years until I moved to Tokyo when I was 12. My life has been a constant balancing of these two different identities, but I really value my dual experience and want to bring these two different cultures and ideologies together.

I used to struggle with both my physical and emotional wellbeing, but I have found that by adopting a healthy lifestyle, I have worked myself into a positive feedback loop– a healthy body supports a healthy mind, and a healthy mind builds a healthy body.

Using the lessons I’ve learned from and experienced in both my Japanese and Western upbringing, I’ve managed to help myself by following a philosophy based on wellness and health. I strongly believe that good health is not just beneficial, but incredibly essential to living a fulfilling and rich life.

My journey is far from perfection, but I use my personal experience and dual knowledge of Japanese and Western lifestyles to help others shape healthy, sustainable, and fulfilling lifestyle paths toward better living.

My goal is to empower you with the strength that you can control your own well-being.




About Kaki Okumura

Kaki Okumura is a Japanese food and wellness writer, helping others discover simple ways to approach food, movement, and rest, so they can reach higher levels of lifestyle balance and ultimately, contentment.