Japan Research and Analysis
through Internet Information

by Yasuharu Dando

Men Getting Fatter, Women Getting Thinner
(Japanese edition:2000/04/20)

The Outline of the Results of the 1998 National Nutrition Study published by The Ministry of Health and Welfare last spring became a topic of discussion, because of its revelation of the contrasting trends among men and women of the younger generation. During the 19 years since the previous Survey in 1979, there had been an obvious increase in the numbers in both the categories of "overweight" young men and "thin" young women.

Fatter Men and Thinner Women: A Dramatic Trend in the Younger Generation

According to the National Nutrition Survey, the percentage of overweight young men has doubled, reaching a peak of 30% in the 30s age group, with rather high figures in the older generations as well. In stark contrast, for women in their teens, 20s and 30s, the percentage of "thin" women has increased dramatically. For further details, see the table below.

The Percentage of Obesity in Different Age Groups
Age Group   15-19   20-29   30-39    40-49   50-59   60-69   70 or older
1979         6.0     9.2     16.3     21.3    19.1    16.5      14.6
1998        11.4    19.0     30.6     29.0    29.0    29.8      20.1
1979         4.5     7.1     14.1     24.7    27.7    26.9      25.1
1998         6.1     7.0     13.9     19.5    26.3    31.3      27.1

The Percentage of Thinness in Different Age Groups  
Age Group   15-19   20-29   30-39    40-49   50-59    60-69   70 or older
1979        15.3     8.4      4.3      4.1     6.0     9.5      17.0
1998        16.3     8.3      3.8      3.6     2.8     4.0      11.6
1979        13.5    14.4      9.2      4.7     6.1    10.2      12.5
1998        20.4    20.3     12.8      4.5     4.3     3.7      10.6

The trend towards obesity in men continues through all the age groups up to the top. For women, on the other hand, the amount of change in the statistics for thinness in the younger age groups is what stands out. Adding to this the fact that the proportion of overweight women in their 40s has decreased by quite a large percentage, we are drawn to the conclusion that the trend towards thinness in young people has progressed considerably. Looking at it from a different point of view, we can see that the mothers of the so-called "baby boom generation" are the epicenter of this trend towards thinness, which extends to their teenage daughters.

The categories of being "obese" or "thin" are determined on the basis of a calculation of Body Mass Index (BMI), which you can work out for yourself. To obtain your BMI, divide your weight in kilograms by the square of your height in meters. The standard is 22 and "25 or more" is considered overweight, while a score of "18.5" is classified as thin. For example, for a man with a height of 1.7 meters (170 cm.), a weight of 72.25 kg. or more is classified as overweight, while for a woman with a height of 1.6 meters (160 cm.), 47.36 kg. or less is classified as thin.

The Large Gap in the Desire to Control One's Weight

There is a huge gap between men and women in terms of the desire to bring one's weight closer to the ideal. In this survey, although as many as 70 - 80% of women in all the age groups do have this kind of awareness, this is true for only about 50% of the men. Even if they are overweight, more than 40% of men are not making any efforts to control their weights.

If we look at another category in the survey, the state of mind of men becomes even more obvious. In response to the question, "When will you begin to be careful about the amount of food you eat or its contents?" 80% of men aged from 20 to 49 replied, "I have no plans to do anything about this issue in the near future."

The frequency of drinking alcohol increases for men in their late 20s through to their 30s. Those who drink "almost every day" reach figures of 17.3% in their late 20s and 38.9% in their 30s, and this percentage increases even more in the older age groups, to about half of the subjects. When asked to explain the reason for the recent increase in the number of occasions when they drink alcohol, the reply for many men in their 20s and 30s is "It's because of an increase in drinking occasions related to work," while for those in their 40s, a common response is "Itfs because I feel more stress now."

While it is true that being overweight is a product of today's stressful society, fundament-ally the cause lies in the history of the human race, with its four million years of starvation. "In order to efficiently store up in the body the energy obtained from food, all the extra energy must be converted into fat and stored beneath the skin or in the internal organs. In other words, human beings needed to fight starvation by mastering the ability to accumulate a large amount of fat inside the body."

If you have ten kilograms of fat in your stomach, this is equivalent to one month's worth of calories. This means that you have a storage room inside your body such that, should you have the misfortune of being shipwrecked somewhere, as long as you have water, you can survive for some time.

If we do not take these kinds of physical characteristics into consideration and just eat whatever we feel like, without doing any exercise in particular, it would actually be abnormal NOT to put on weight.

In contrast, the fact that more women are being classified as "thin," as can be seen in the results of the survey, shows that the concept of the "ideal weight" is becoming lower and lower. Evaluated in terms of percentage of fat in relation to weight or "rate of body fat," more than 20% of men and 25% of women were overweight. This 5% gap between men and women can be explained by the fact that women have to undergo the great burdens of pregnancy and childbirth, and so the 5% extra is "security" to cover the energy needed for these activities. For young women nowadays, even such a small gap appears to be seen as a nuisance.

The Body's Design Enables the Calories from Alcohol to Disappear as Heat

Here we will introduce two pieces of knowledge that may seem to contradict common sense. First, people tend to think of alcoholic drinks as a major enemy in the fight to maintain an ideal weight, but this point of view has changed as a result of recent research. Specifically, "one big difference between alcohol and other sources of calories is that alcohol and its metabolic products cannot be stored up inside the body. Also, since alcohol itself does not include elements needed by the body, such as vitamins and protein, the calories obtained from alcohol are calories without content or what are called "empty calories". So, in contrast to an equal amount of calories that have been obtained from other foods, they contribute almost nothing."

A large can of beer is said to contain about 256 kilo-calories, but according to this theory, calories obtained from alcohol are excluded, and so the number of calories counted, that is, those from the sugars, etc., end up as only about one third of this figure. Distilled spirits like whisky and gin do not include sugars, etc., so they have "zero calories." The reason that people drink alcohol and then gain weight is that the snacks which they tend to eat along with the drinks consumed often have an extremely high caloric content. In addition, the fact that such snacks tend to be eaten in the evening when the digestive organs are more active than in the daytime probably exacerbates this phenomenon.

We all know people who are great eaters but stay slim. This is not only because the rate of absorption of food eaten differs from person to person, but also because such people have a superior ability to release the calories consumed, in the form of heat. Compared to their white-colored fat cells, whose purpose is the storage of fat, these people have active brown-colored fat cells, which exist for the aim of maintaining and adjusting body temperature.

According to an experiment on the degree of difference between individual people in the generation of heat after eating, about one tenth of the calories obtained from food is used for assimilation by the internal organs. As well as this, as you have probably experienced, it is common to perspire immediately after eating. People tend to sweat profusely around the neck and shoulders, places where there are high concentrations of brown-colored fat cells. It is said that the heat generated by these cells amounts to as much as a maximum of 800 kilo-calories per day and also that cayenne pepper has the power to activate heat generation.

Furthermore, at the Medical Department of Aichi University, research on obesity and the consumption of energy is steadily progressing, focusing on the factors that may potentially activate the brown-colored fat cells. This research seeks to detect elements resembling the protein which activates the brown-colored fat cells, and exists widely throughout the composition of the body, not only in brown-colored fat cells. For example, it is said to be related to heat productivity in the physique and the muscles.

Sports players have a high basic body metabolic amount, and so are able to release as heat the equivalent amount of the calories they had consumed. I had always thought that it was too much to believe that the role of heat generation is performed only by the brown-colored fat cells, which exist only in limited places, so research on the existence of protein to activate heat generation, that works over a wide area, made a lot of sense to me. Changing the body into the physical type that would transform the extra energy throughout the body into heat and release it, specifically means things like using exercise as a method of treatment for medical problems such as diabetes, etc.

The Importance of Breakfast to Increase Intelligence

If we consider the starvation-marked history of the human race, the trick to preventing obesity is not to let your body experience the feeling of starvation. Practically applied, this includes the fear of having a "rebound" later, even if you do manage to succeed in losing weight for a while. There is a lot of material about this on the Internet. If you use a search engine to look up "rebound," you can find all kinds of information. The feeling of starvation during the period of the diet actually improves the body's ability to absorb, so that when some extra food comes in to the body, it will be changed to fat more efficiently than it was before.

Even without going to such extremes, it is said that people who eat only two meals a day are more likely to put on weight than those who eat three meals a day, because the period of "starvation" in between meals is longer for the former. In previous National Nutrition Surveys, there was a question about the times when meals were eaten. If we look at the answers, we see that a full half of the men surveyed did not eat meals at a fixed time.

This confirms the importance of eating breakfast. A study was made of the academic achievements of students at Jichi Medical School after they had entered the school, and the results apparently showed that "comparing the geographical areas they came from, their physical builds, and all kinds of other characteristics found no correlative relationship at all with their achievements at school, while the single factor that did have a correlation was whether or not they ate breakfast."

Why were results like these obtained? One reason is that, by eating breakfast, the body changes its state from the sleep of the night before to wakefulness, and that in order to use the brain for something like study, the glucose just freshly obtained from food is essential. The energy used by the brain cannot be extracted from fat cells or other similar sources. In addition, there is the phenomenon that fiber bud cell growth factors (FGF), which promote memory and improve the benefits of study, increase as a result of eating food.

(special thanks to translation by PHP Institute Inc.
"JAPAN CLOSE-UP" November 2000)

[Top Page]

p.v. since Dec 2000
[Related Links]
Topsites Japan Popular Japan related directory
Stanford University - JGuide Directory
electronic journal of contemporary japanese studies
Useful Links - Staffordshire University Business School