Why Are Sumo Wrestlers So Fat?; Six Reasons They’ve Adapted to the Gut Starvation Mechanism


  1. The same mechanism as people who rebound after dieting
  2. The six reasons that I believe it is a starvation mechanism
    The bottom line


Have you ever seen a sumo wrestler right in front of you? When I was working as a waiter at a hotel several years ago, there was a pep rally for sumo wrestlers, and I was able to see them up close.

Also, at the 2017 Osaka tournament in Japan, I observed the morning practice of a team and was allowed to sample their breakfast called "chanko."

meal called chanko

I had a sample of "chanko."

sumo wrestler

I got the impression that they are big-boned, with steel-like muscles, and a lot of body fat on top of that.  

Their average body fat percentage is said to be around thirty percent or more, but there are some wrestlers in the twenty percent range, not that different from the average person. They are like a mass of muscles. 

It is generally believed in Japan that wrestlers will gain weight because they eat a lot and sleep well including taking naps, but I can explain that they have successfully adopted the mechanism of intestinal starvation.

1. The same mechanism as people who rebound after dieting

In Japan, the image of sumo wrestlers in particular may lead to the image that "eating more makes you fat," but I would like to explain that this is the same mechanism as "those who end up rebounding after dieting and gain more weight than before" or "those who gradually gain weight by skipping breakfast or having a late dinner.”

First of all, I'm going to illustrate how both of them gain weight in the figure below. 

■The concept of a person who gains more weight than before after dieting


(1) You will lose a little weight through caloric restriction or exercising, etc.

(2) When you eat less (especially with an unbalanced diet), and you feel hungry for an extended period of time, you tend to starve your gut, and your base weight may go up without you realizing it. 

(3) Later, when you start eating as you did before dieting, your weight will be higher than before.

■The concept of sumo wrestlers gaining weight


(1)First, by their traditional unique diet and hard practice, intestinal starvation can be induced. Their base weight goes up. 

(2)Then, they eat a lot and thire actual weight increases (weight gain).

If you are a dieter, there is a time lag, but in the case of wrestlers, they eat good amounts of food every day, so it happens almost simultaneously.

Although they appear to eat a lot and are gaining weight, if intestinal starvation is not induced, their weight should not increase as much as expected.

2. The six reasons that I believe it is a starvation mechanism

When you see big eaters in a food eating competition, some may ask, "Why don't they get fat even though they eat so much?” But, from my theory, it is not at all surprising.

It’s not that they have a special "non-fattening constitution," but that anyone who eats like that from morning to night is less likely to gain weight (although I wonder why they can eat so much food at once).

Please understand that the way of eating of a sumo wrestler is a far cry from that of an eating competitor.

■An explanation of why the way of eating and exercising of sumo wrestlers can easily induce intestinal starvation. (1) - (6) 

(1)A wrestler must weigh at least sixty-seven kilograms to be admitted. People who are overweight or muscular from the beginning tend to have stronger stomachs, and are thought to have a relatively high digestive rate. Such people are more likely to induce gut starvation than thin people.

a chanko dish

(2) The basic diet for sumo wrestlers is called "chanko," which consists of easily digestible proteins such as chicken, fish, tofu, etc., and vegetables, slowly simmered in soy sauce. It is relatively low in fat and easy to digest. 

(3) Sumo wrestlers generally eat a good amount of rice. By eating a lot of rice and soup, the stomach expands (the balloon effect), which leads to creating the dilution effect and push-out effect of food in the stomach.

[Related article]

The Dilution Effect/ Pushing Out Effect of Carbohydrates

(4)They traditionally eat two meals a day: the first meal is around eleven a.m. after morning practice, and dinner is around six p.m.
Since they practice from the early morning without breakfast, if dinner is finished at seven p.m., it means that they do not eat for about fifteen to sixteen hours until the next meal. It make sense to do intense morning training on an empty stomach to gain weight.

Of course, there are some wrestlers who try to eat snacks or supplements late at night in order to take in more calories, but my idea is that it makes easier to gain weight when they don't eat.

morning practice of sumo wrestler

(5)Strength training is a force for gaining strength, and it ultimately works in the direction of weight gain. Eating two meals a day and exercising intensely will make sumo wrestlers gain more weight.

(6)Most of the food in the pot is eaten first by the top-ranked wrestlers. The lower-ranked wrestlers eat next, and lastly the new trainees. 

The last people have to eat a big ball of rice and leftovers, which consists of only a little meat and most of the soup.
it is said that this kind of meal tends to make sumo wrestlers gain more weight.

The bottom line

(1)Sumo wrestlers are famous for being big and fat, but they do not gain weight because their daily caloric intake exceeds their daily caloric expenditure.
Their traditional diet and exercise makes sense in terms of weight gain in that it facilitates the creation of intestinal starvation.

(2)Intestinal starvation is more likely to be induced when a person who has a big body from the start eats relatively easily digestible foods with lots of carbohydrates (rice) and two meals a day.

(3)The mechanism by which wrestlers gain weight is the same as that of "people who diet and gain more weight than before due to the rebound effect.”
In the case of sumo wrestlers, since they eat a lot every day, this happens almost simultaneously, and they appear to eat a lot and gain weight.