Differences in eating habits between Japanese and Westerners
A friend of mine living in the United States mentioned that many Americans tend to be overweight, and globally, obesity is a serious health concern.
Obesity not only increases the risk of lifestyle-related diseases but also shortens overall healthy life expectancy.
The World Health Organization (WHO) recognizes obesity as a major public health issue, and addressing it is an urgent priority.
On the other hand, Japan, where I live, is known for having one of the lowest obesity rates in the world, and people here tend to live long and healthy lives.
I believe this difference in obesity rates is largely due to the differences in dietary habits between Western countries and Japan.
Therefore, I compared the obesity rates of major Western countries (the United States, the United Kingdom, Germany, and France) with that of Japan, examined the characteristics of their respective diets, and then proposed ten Japanese food items that Westerners with obesity should incorporate into their diet for a healthier lifestyle.
I will explain the nutritional benefits of these foods and their contribution to a healthy diet in detail, and I have also looked into how Japanese dietary habits are related to the lower incidence of obesity and other lifestyle-related diseases.
Table of Contents
Comparison of Obesity Rates in Major Western Countries and Japan
Obesity rates in the United States remain high.
According to estimates from the Centers for Disease Control and Prevention (CDC), 40.3% of adults were obese based on survey data from 2021 to 2023.
A 2024 study published in the medical journal “The Lancet” found that nearly three out of four American adults are overweight or obese, a sharp increase compared to the 1990s, when just over half of adults were obese.
The obesity rate is highest among adults aged 40 to 59 at 46.4%, and it has also been reported that obesity rates vary by education level.
CDC: https://www.cdc.gov/nchs/products/databriefs/db508.htm
Obesity is also a significant issue in the United Kingdom.
A 2022 survey found that 29% of adults in England were obese, and 64% were overweight or obese.
The obesity rate has increased from 15% in 1993 to 29% in 2022, with men being more likely than women to be overweight or obese. Adult obesity rates also tend to increase with age.
NHS: https://digital.nhs.uk/data-and-information/publications/statistical/health-survey-for-england/2022-part-2/adult-overweight-and-obesity
In Germany, data from 2019-2020 shows that 53.5% of adults were overweight (including obese), and 19.0% were obese.
Men are more likely than women to be overweight, but there is no gender difference in the prevalence of obesity. Germany’s obesity rate has been steadily increasing since 1990.
NHI: https://pmc.ncbi.nlm.nih.gov/articles/PMC9520353/
A 2020 survey in France indicated that 17% of the population was obese, and 47.3% of adults were overweight or obese.
France’s obesity rate has doubled in the past 25 years, with higher rates particularly in northern and northeastern France.
In recent years, the increase in obesity has been most noticeable among young adults aged 18 to 24.
NHI: https://pmc.ncbi.nlm.nih.gov/articles/PMC9918095/
On the other hand, Japan’s obesity rate (BMI of 30 or higher) is very low, at less than 4%, and about 20% of adults are overweight with a BMI between 25 and 30. A 2022 survey by the Ministry of Health, Labour and Welfare found that 31.7% of men and 21% of women had a BMI of 25 or higher. A 2020 report using WHO criteria (BMI of 30 or higher) showed that 4.3% of women and 6.0% of men were obese.
globalnutritionreport: https://globalnutritionreport.org/resources/nutrition-profiles/asia/eastern-asia/japan/
| Country | Obesity Rate (WHO Standard, BMI≧30) | Data Year |
| United States | 40.3% | 2021-2023 |
| United Kingdom | 29% | 2022 |
| Germany | 19% | 2019-2020 |
| France | 17% | 2020 |
| Japan | Less than 4% | 2020 |
Dietary Differences: Westerners vs. Japanese
The typical Western diet tends to be high in processed foods, refined grains, red and processed meats, sugary drinks, sweets, fried foods, and high-fat dairy products.
On the other hand, the consumption of fruits, vegetables, whole grains, fish, and legumes tends to be low.
Another characteristic is the large portion sizes per meal.
In contrast, the traditional Japanese diet (Washoku) that we eat daily is based on rice as the staple food, along with a menu centered on seafood, soy products, seaweed, and vegetables.
The intake of red meat, fats, and dairy products is moderate, and cooking methods that emphasize the natural flavors of the ingredients are valued.
Umami is effectively used to reduce the amount of salt needed.
Meals feature seasonal ingredients and a style of consuming small portions of a variety of dishes.
However, modern Japanese dietary habits have changed due to Western influence, with increased consumption of meat, bread, and dairy products.
The consumption of processed foods and sweets is also increasing.
There have also been recent reports of declining vegetable and fruit intake due to rising prices.
Nevertheless, Japan’s obesity rate remains low compared to Western countries.
When comparing the consumption of processed foods, ultra-processed foods account for 58% of adult diets in the United States and 57% in the United Kingdom, while in Japan, it is only 28%.
In the UK, more than 50% of the average calorie intake comes from ultra-processed foods.
Japan also tends to consume more seafood than Western countries.
Vegetable intake is similar between Japan (about 281g per day in 2019) and wealthy Western countries (about 300g), but the types and cooking methods of vegetables are likely different.
Consideration of Dietary Habits Leading to Differences in Obesity Rates
Several factors in dietary habits likely contribute to the difference in obesity rates between Western countries and Japan.
First, calorie intake and portion sizes can be mentioned.
In the West, portion sizes are generally large, which often leads to higher calorie intake.
Japanese cuisine emphasizes the natural flavors of ingredients (“subtractive cooking”), while Western cuisine often involves adding butter and sauces (“additive cooking”), which is also thought to have an impact.
The difference in the types of fats consumed is also important
American diets tend to be high in saturated fats, while traditional Japanese diets are characterized by a high intake of healthy polyunsaturated fatty acids such as DHA and EPA found in seafood.
There are also differences in the types of carbohydrates consumed.
Western diets tend to be high in refined grains and sugary drinks, while the Japanese diet is based on rice as the staple food.
The difference in the intake of processed foods is considered to have a significant impact on obesity rates.
Ultra-processed foods tend to be high in calories, fat, sugar, and salt, while being low in essential nutrients and dietary fiber.
There is also a difference in dietary fiber intake between Western countries and Japan.
Japanese diets often include opportunities to consume dietary fiber from vegetables, seaweed, and whole grains, while in the West, dietary fiber intake often falls short of recommended amounts.
Dietary fiber is important for preventing obesity because it helps maintain a feeling of fullness and suppresses rapid increases in blood sugar levels.
Furthermore, cultural differences in eating habits are also thought to play a role.
Japanese people tend to eat balanced meals slowly and savor their food, while Westerners may be more susceptible to convenience and marketing influences, and meals are often consumed quickly.
Incidence Rates of Diabetes and Cancer: Comparison Between Western Countries and Japan
In 2021, the prevalence of diabetes in the United States was 11.6%, with over 90% being type 2 diabetes. In the UK, the prevalence of type 2 diabetes in adults aged 16 and over in England in 2021 was estimated to be 7.8%. In Germany, approximately 8.9 million people were diagnosed with diabetes in 2023, with over 90% having type 2 diabetes.
The prevalence of diabetes in adults in France in 2021 was 8.6%. On the other hand, the prevalence of diabetes in adults in Japan in 2021 was reported to be 11.8%.
However, the figures may vary depending on diagnostic criteria and survey methods, and considering the low obesity rate, the prevalence of type 2 diabetes may also be lower in Japan than in Western countries.
Let’s also compare cancer incidence rates.
In the United States, 1,777,566 new cancer cases were reported in 2021, with the most common being breast cancer, prostate cancer, lung cancer, and colorectal cancer.
In the UK, 395,181 cancer cases were reported in 2021, with breast cancer, prostate cancer, colorectal cancer, and lung cancer being the most common.
In Germany, approximately 493,200 new cancer cases were estimated in 2020, with breast cancer, prostate cancer, colorectal cancer, and lung cancer being frequently observed.
In France, an estimated 433,136 new cancer cases were reported in 2023, with breast cancer, prostate cancer, and lung cancer being the most common.
In Japan, an estimated 1,019,000 new cancer cases were reported in 2022, with colorectal cancer, lung cancer, stomach cancer, breast cancer, and prostate cancer being prevalent.
Japan has a higher incidence rate of stomach cancer, while the incidence rates of colorectal cancer, breast cancer, and prostate cancer are considered to be lower compared to Western countries.
NHS: https://www.england.nhs.uk/blog/millions-of-people-have-diabetes-but-how-much-do-you-know-about-it/
Analysis of the Relationship Between Dietary Differences and Health Conditions
The Western diet, being high in calories, fat, sugar, and low in fiber, is suggested to easily lead to obesity and insulin resistance, increasing the risk of type 2 diabetes. Furthermore, a diet high in animal fat and red meat may increase the risk of certain cancers (such as colorectal, breast, and prostate cancer).
On the other hand, the Japanese diet, being low in fat and high in seafood and soy products, as well as rich in dietary fiber, is thought to help control visceral fat accumulation and aid in weight management.
Moreover, the consumption of soy products is suggested to potentially reduce the risk of type 2 diabetes, especially in women.
In addition, the intake of soy foods, which is characteristic of the Japanese diet, may be related to the lower incidence of breast and colorectal cancers.
However, the relationship between diet and health conditions is complex, and it is necessary to consider the influence of genetic factors, lifestyle habits (lack of exercise, smoking, etc.), and access to medical care.
10 Japanese Foods That Westerners with Obesity Should Incorporate into Their Diet
Based on the above analysis, I propose ten Japanese food items that Westerners with obesity should incorporate into their diet for a healthier lifestyle:
- Nori (seaweed sheets)
Low in calories and rich in dietary fiber, minerals, and vitamins. - Wakame (seaweed)
Low in calories and high in iodine, minerals, and vitamins, supporting metabolism. - Konbu (kelp)
Rich in iodine and dietary fiber, it can promote satiety and improve the intestinal environment. - Tofu (soybean curd)
High in protein and low in calories, it helps maintain satiety and aids in weight management. - Edamame (soybeans in pods)
High in protein and dietary fiber, low in calories, and a satisfying food. - Miso (fermented soybean paste)
Rich in probiotics, improving the intestinal environment, and a low-calorie, flavorful seasoning. - Shirataki (konjac noodles)
Almost calorie-free and rich in dietary fiber, promoting satiety and helping to control rapid increases in blood sugar levels. - Shiitake (mushrooms)
Low in calories and carbohydrates, rich in dietary fiber, B vitamins, and antioxidants. - Green Tea (Ryokucha)
Contains catechins and caffeine, which may promote energy metabolism. It also has antioxidant properties. - Salmon/Mackerel/Tuna (Sake/Saba/Maguro)
Rich in high-quality protein and omega-3 fatty acids, promoting satiety and supporting heart health.
Nutritional Benefits and Contribution to a Healthy Diet of Each of the 10 Selected Japanese Foods
- Nori
Rich in various minerals, vitamins A, B complex, C, as well as protein and dietary fiber.
It is low in calories yet highly nutritious, and the dietary fiber promotes satiety, supporting healthy weight management. - Wakame
Very high in iodine, which is essential for maintaining thyroid function.
It is also rich in manganese, folate, magnesium, calcium, and vitamins A, C, E, and K. Despite being low in calories, it is packed with nutrients and contains dietary fiber, which may help with weight management. - Konbu
Rich in iodine, calcium, various vitamins, and dietary fiber.
The dietary fiber has a prebiotic effect, helping to improve the intestinal environment. It can also help maintain a feeling of fullness. - Tofu
Rich in high-quality plant-based protein and contains all essential amino acids.
It is also rich in calcium and magnesium, and is low in calories and saturated fat.
Being high in protein, it helps you feel full and contributes to weight management. - Edamame
Very rich in protein and dietary fiber, and low in calories.
It contains all essential amino acids and is a highly nutritious food.
The dietary fiber aids digestion and promotes satiety, making it effective for weight management. - Miso
A fermented food rich in probiotics.
It is expected to improve the intestinal environment and aid digestion.
It is also rich in protein while being low in calories and can be used as a flavorful seasoning. - Shirataki
Its main component is glucomannan, a water-soluble dietary fiber, and it is almost calorie-free.
It expands when it absorbs water, making it easy to feel full and helping to reduce food intake. It may also contribute to stabilizing blood sugar and cholesterol levels. - Shiitake
Rich in B vitamins, vitamin D, dietary fiber, minerals such as potassium, and antioxidant compounds.
It is low in calories yet highly nutritious and may help improve immunity and maintain heart health.
The dietary fiber promotes satiety and supports weight management. - Green Tea
Rich in catechins, a type of polyphenol, which have antioxidant properties.
It also contains caffeine, which may promote energy expenditure.
It is also expected to have an effect of slowing down the rise in blood sugar levels after meals. - Salmon/Mackerel/Tuna
Rich in high-quality protein and omega-3 fatty acids such as DHA and EPA.
Omega-3 fatty acids are known to reduce the risk of cardiovascular diseases.
Protein also helps maintain a feeling of fullness, thus aiding in weight management.
Consideration of How the Japanese Diet is Related to the Low Incidence of Obesity, Diabetes, and Cancer, and the Potential Benefits of Incorporating the 10 Selected Japanese Foods into the Western Diet
The Japanese diet is characterized by a balanced nutritional intake, a combination of diverse ingredients, cooking methods that bring out the natural flavors of the ingredients, and moderate portion sizes.
These factors work together to contribute to the low incidence of obesity, type 2 diabetes, and certain cancers.
In particular, the high intake of seafood and soy products, the abundance of dietary fiber, and the low intake of processed foods are thought to contribute significantly to maintaining health.
By incorporating these Japanese foods into their diet, Westerners with obesity can expect the following potential benefits: First, consuming foods rich in dietary fiber (nori, wakame, konbu, edamame, shirataki, shiitake) can make it easier to feel full, potentially leading to a reduction in overall calorie intake. Low-calorie yet highly nutritious foods (nori, wakame, konbu, tofu, edamame, shirataki, shiitake, green tea) support healthy weight management.
Omega-3 fatty acids found in seafood (salmon, mackerel, tuna) promote cardiovascular health and may have an anti-inflammatory effect.
Soy products (tofu, edamame, miso) are a good source of high-quality protein, which not only helps maintain satiety but also suggests the potential to reduce the risk of certain chronic diseases.
Catechins in green tea have antioxidant and metabolism-boosting effects.
However, simply adding these Japanese foods to a Western diet may not be enough to fully reap the benefits of the entire Japanese dietary pattern.
It is important to review overall eating habits, including portion sizes, balance, and cooking methods.
Conclusion
In this blog post, I have discussed the significant difference in obesity rates between Western countries and Japan and the dietary differences behind it.
Of course, there are overweight people and those with lifestyle-related diseases in Japan as well, but the Japanese diet is characterized by low fat, high fiber, abundant intake of seafood and soy products, and low consumption of processed foods, which I believe may be related to the low obesity rate and the low incidence of type 2 diabetes and certain cancers.
By actively incorporating Japanese foods such as nori, wakame, konbu, tofu, edamame, miso, shirataki, shiitake, green tea, and salmon/mackerel/tuna, Westerners with obesity may experience improved satiety, reduced calorie intake, improved blood sugar and lipid profiles, and overall better health.
Improving one’s diet has the potential to greatly contribute to health and well-being.
So, if you can get your hands on these ingredients in your town, why not give them a try in your cooking?
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