Why Japan Has Remarkably Low Obesity Rates

I recently returned from a ski trip/medical meeting to Japan. We were on the island of Hokkaido, which receives the most snowfall in Japan. They set records this year, over 10 feet of snow! Besides the snow and powder, I was impressed by the lack of obesity where we traveled. Out of 8 days of travel and seeing thousands of people, I could count on one hand the number of obese people I saw...and they weren't Japanese. Thus, I decided to do some research and delve further.

Aerial photo of the city of Sapporo on the island of Hokkaido with the mountains in the background.

Japan has an obesity rate of only 4% in adults, one of the lowest in the world. In contrast, the United States rate is over 40%, ten times that of Japan. Why such a stark contrast? Diet? Lifestyle? Genetics? You will not find massive sales of Ozempic and other weight loss meds here; I wanted to learn why.

Dietary Differences

While in Japan, we were on the island of Hokkaido, surrounded by the sea. Thus, fresh seafood abounded. Our meals were filled with fish, rice, ramen, and sushi.

The traditional Japanese diet is filled with white rice, fish, soybean products, seaweed, pickled and fermented foods, and green tea. Even their fast food and street food items have these components. Their diet is fresh and mostly unprocessed, and they are not snackers. What surprised us were the 7-11 stores, filled with food made fresh daily, and healthy, traditional foods. They had a limited amount of snack foods. Japan also has more vending machines than any other country, they are everywhere! However, most are for beverages and filled with coffee (mostly black), teas, waters, flavored waters, and a few sodas. A typical machine holds 30 beverages and out of these only 4-6 slots are soda, usually in the bottom row.

A typical vending machine with beverages. Despite the words CocaCola at the top, only 4 items of soda are available out of the thirty drinks.

The breakfast buffet at our hotels was amazing and served food from all meals, including eggs, waffles or pancakes, salad, fish, soup, vegetables, etc. The waffles and pancakes are a fraction of the size we normally have in the states, only 3-4 inches. Nothing is super-sized.

A few photos taken from our Japanese breakfast buffet. Note the array of vegetables (top photo), salad bar (middle photo) and the small size of the pancakes (bottom photo).

Japan consumes less meat and beef, milk and dairy, sugar and sweeteners, and fruit and potatoes than the US. Their primary protein sources are fish and soy products. Compared to other countries, their sugar-sweetened beverage intake is much lower. Their dietary components provide healthy, polyunsaturated fats, DHA and EPA, low sugar content, fermented foods, phytonutrients, and antioxidants. These contribute to lower rates of obesity, type 2 diabetes, and cardiovascular disease.

In contrast, the US diet has more meat, beef, dairy, ultra-processed foods, and sugar-sweetened beverages, thus more saturated fat and sugar. We have higher rates of the same diseases. The US consumes about four times the amount of beef and over twice as much sugar, giving us a more inflammatory diet. The Japanese soy intake is about 200 times higher, and their green tea intake is more than double that of Americans. Their intake of vitamins D and K is also higher. 

A typical meal in Japan will have five to six portions, but each portion is small. A meal might consist of portions of fish, rice, miso soup, pickles, and vegetables. Portions are small but variety is great.

A traditional Japanese meal with multiple small portions with meat or fish, soy, vegetables, and fermented foods.

Japan considers their cooking style a “minus” cuisine  - not adding extra but bringing out the natural flavors of the food. In contrast, Western cooking is a cuisine of addition - adding butter, salt, sauces, herbs, and chemicals to make food tastier.

Another difference is that the Japanese are taught at a young age to stop eating when they are 80% full. In other words, they refrain from stuffing themselves or overindulging. This allows the body to sense when it has had enough. Meals are a social event and it is against custom to eat on the go. People don't eat or drink as they are walking in the city. If they purchase food on the streets, they take it with them or stop, eat, and take away their trash. You don't see any trash in town, despite not finding trashcans either. People are expected to take their trash home to dispose if trashcans aren't available.

Lifestyle

School children walking to school which is the primary mode of transportation.

The Japanese are more physically active than Americans, simply walking more… a lot more. They rely on walking, biking, and public transportation more than automobiles. There is an emphasis on daily movement rather than gym workouts. Exercise is part of their daily life. Their school policies emphasize balanced meals, nutrition education, and physical activity. We saw many school groups on the ski slopes. The schools on the island send students weekly to ski and enjoy winter sports.

In 2008, Japan started a nationwide screening program in which all adults, ages 40-74, were screened annually for obesity and metabolic syndrome by doctors and nurses at workplaces. This was required by law. If found to be at risk, they were provided with intensive lifestyle interventions to reduce weight and improve cardiovascular status. All Japanese health insurers must provide lifestyle modification programs for their insured diagnosed with metabolic syndrome. They use smart devices to monitor patient’s health. Russia has now adopted some Japanese methods and technologies for weight control.

The Japanese have a strong sense of community and social circles, where they stay active with each other through walking, yoga, tai chi, dance, and gardening. They don’t think of retirement but of a continued reason for being, having a strong sense of purpose. Older Japanese continue to maintain an active lifestyle as much as possible.

Japanese adults practicing tai chi together outdoors as a social group.

Caveats

Japanese immigrants to the US develop much higher rates of obesity and type 2 diabetes than Japanese living in Japan. Thus, their lack of obesity points to environment and lifestyle rather than genetic factors. Over time, with the adoption of a Western diet, Japanese Americans become as overweight as the Americans they live among. Even in Japan, cities that have a prevalence of fast food have seen rising obesity rates. Okinawa, one of the Blue Zone regions with some of the longest-living people, has now become an area of Japan with the highest rate of obesity in the young as it has become Americanized.

Final Thoughts

It is interesting that two of the most affluent countries in the world have such differences in health and life expectancy. Japan has one of the highest and most active life expectancies; the US ranks 48th, according to rankings by Worldometer in 2024. However, Japanese who live in the US and adopt the Western diet and lifestyle quickly develop similar rates of obesity and health issues as that of Americans. This speaks volumes and should be a wake-up call to us all.