Posted: Sat 11 Apr 2009 00:09 Post subject: Black women in the U.S. appear to be shrinking
Black women in the U.S. appear to be shrinking
They’re shorter on average than a generation ago, federal study says
By Tom Hundley
December 25, 2008
Call her The Incredible Shrinking African-American Woman.
In an age when the adult populations of most industrialized nations have grown significantly taller, the average height of black women in the U.S. has been receding, beginning with those born in the late 1960s.
The difference in stature between white women and black women has now stretched to three-quarters of an inch and appears to be increasing, according to newly released data from the National Health and Nutrition Examination Survey (NHANES) conducted by the federal Centers for Disease Control and Prevention.
The main culprit appears to be diet.
The average height of a black woman born in the 1980s is just under 5 feet 4 inches; her mother, born in the 1960s, is more than half an inch taller. Even her grandmother, born in the 1940s, is a bit taller. The average white woman born in the 1980s is about half an inch taller than her mother.
The gap is “truly phenomenal,” according to John Komlos, an economist and historian who has made a specialty of studying human heights. “Such a steep decline is practically unprecedented in modern U.S. history.”
You have to go back to the antebellum South to find a similar shrinkage. The generation of white men born in the 1840s who experienced the ravages of the Civil War lost nearly an inch to their Northern counterparts, Komlos said.
A Chicago native who is a professor at the University of Munich, Komlos made a name for himself several years ago when his research revealed that the average height of adult Americans, once the tallest folk to roam the planet, had stopped rising after World War II and has since been surpassed by that of several European nations. The Dutch now lay claim to the title of tallest.
Komlos’ latest findings, based on the NHANES data, suggest that after nearly 25 years of stagnation, the average height of adult Americans born from 1975 to 1986 has edged up again—with the exception of black women, whose height is moving in the opposite direction.
The reason this matters, according to Komlos, is because “height is a very good overall indicator of how well the human organism thrives in its socioeconomic environment.”
His argument is bolstered by another discovery: While the heights of low- and middle-income black women are plummeting, upper-income black women are growing taller and rapidly closing the gap with their white counterparts.
An individual’s height is fixed mainly by genes, but the average height of different categories of people is determined to a large extent by external factors.
Komlos, who has been studying heights since the early 1980s, says the downward trend among black women was “quite unexpected.”
“There have been declines before” in the U.S. population, he said. “But never this quickly.”
Nancy Adler, director of the MacArthur Foundation’s Research Network on Socioeconomic Status and Health, said Komlos’ latest findings were “puzzling” but consistent with what is already known about the impact of income disparity, access to health care and educational levels on a person’s overall well-being.
Also baffling, Adler said, is the disparity between black men and black women, “since they are subject to the same pre-birth conditions” and then grow up in the same environment.
“The only reasonable explanation we can come up with is diet and the obesity epidemic among [middle- and low-income] black women,” said Komlos.
Over the last three decades, the prevalence of obesity among white Americans has tripled, while among blacks it has increased fivefold.
Black females were hardest hit: Almost 80 percent of black females are overweight or obese, compared with 62 percent of the total female population, according to the CDC.
The problem develops early. Twenty-one percent of black females ages 2 to 19 are overweight or obese, compared with 12 percent of white girls.
Another oddity, according to Komlos, is that black children, both male and female, grow faster and taller than their white counterparts in early childhood, but whites catch up and pass them during the teen years.
Pediatric growth experts offer one possible explanation. High caloric intake from an unhealthy diet fuels an early growth spurt among black children, plus it speeds the onset of puberty, especially for black girls, who now begin menstruating 81/2 months ahead of white girls. This early onset of puberty reduces the duration of the critical pre-adolescent growth spurt, resulting in a lower adult height.
People who are short or overweight tend to be more susceptible to health problems than their taller, thinner counterparts. They also tend to produce offspring susceptible to the same problems, thus making the cycle hard to break.
Komlos blames the long stagnation of American growth rates that began in the 1950s and the current obesity epidemic on the one-two punch of television and fast food.
“In my opinion, the pressure to consume is so high on the American population that is very difficult for anyone to withstand the urge,” he said. “Education and income help, but the pressure is pretty overwhelming.”
Joined: 19 Jan 2006 {Posts: 223 } Location: Southern California
Posted: Sat 11 Apr 2009 02:33 Post subject:
Quote:
In my opinion, the pressure to consume is so high on the American population that is very difficult for anyone to withstand the urge,” he said. “Education and income help, but the pressure is pretty overwhelming.
Perhaps that old joke might have a grain of truth; namely that the demise of American society won't be due to war or terrorism, but instead the all-you-can-eat-buffet
In all seriousness though, if indeed obesity plays a major role in the downward trend of height among black women will this trend be found among other populations that have similar issues with obesity. For example, I found the following article below concerning the obesity rates among Native Americans. Will the same downward trend in height be noted as well?
http://www.rapidcityjournal.com/articles/2009/04/08/news/top/doc49db8761e3aa8796027535.txt
There might be some truth to exposure to unhealthy food early and lack of height, but I don't believe economic background would be a factor unless you are solely speaking about urban environments.
People growing up in rural environments or progressive rural to suburban environments are more likely to grow their own food and less likely to have fast food franchises in close proximity, whether poor or not, since it is more the norm culturally to grow what you eat.
If Black American men are not 'shrinking', and I am assuming they are under the same economical and dietary conditions as their female counterparts, then why would the first assumption be that this is because of a poor diet? And is this same thing happening to women of other races that obesity runs in the family? I was thinking maybe Black American men tend to pro-create more with shorter, curvier women while their White counterparts go for thinner taller women, but then that would lead right back to the other conclusion that Black men should be getting these same short genes as well.
The only hypothesis that would make sense in this situation would be Black immigration from other places like Africa and the West Indies where the people are shorter than the general population here. Or maybe a little combination of all three.
Joined: 07 Feb 2007 {Posts: 1829 } Location: Lookin DC Metro, Feelin Geneva
Posted: Mon 13 Apr 2009 19:48 Post subject:
girlfromthenc wrote:
If Black American men are not 'shrinking', and I am assuming they are under the same economical and dietary conditions as their female counterparts, then why would the first assumption be that this is because of a poor diet? And is this same thing happening to women of other races that obesity runs in the family? I was thinking maybe Black American men tend to pro-create more with shorter, curvier women while their White counterparts go for thinner taller women, but then that would lead right back to the other conclusion that Black men should be getting these same short genes as well.
The only hypothesis that would make sense in this situation would be Black immigration from other places like Africa and the West Indies where the people are shorter than the general population here. Or maybe a little combination of all three.
Could it be that due to the hormonal differences between women and men that women are somehow adversely effected to something else in their environment or even by food. For instance, I have read that heavier girls (due to being overweight) menstruate earlier because some hormone that is triggered by maintaining higher body fat triggers maturation in women.
I have never read that overweight boys s@xually mature faster than women. This could be because there have not been studies on this, I'm not sure. I'm just throwing out possibilities...that maybe men and women are not effected by the same input in tandem.
It could be possible that early maturation leads to less height or some unknown factor in the diet is changing women and not men.
but then that would lead right back to the other conclusion that Black men should be getting these same short genes as well.
Right.
Not necessarily. As explained to me by a doctor friend of mine, changes in diet can lead to changes in puberty times that can lead to shorter growth spurts in women that would not affect men.
If Black American men are not 'shrinking', and I am assuming they are under the same economical and dietary conditions as their female counterparts, then why would the first assumption be that this is because of a poor diet? And is this same thing happening to women of other races that obesity runs in the family? I was thinking maybe Black American men tend to pro-create more with shorter, curvier women while their White counterparts go for thinner taller women, but then that would lead right back to the other conclusion that Black men should be getting these same short genes as well.
The only hypothesis that would make sense in this situation would be Black immigration from other places like Africa and the West Indies where the people are shorter than the general population here. Or maybe a little combination of all three.
Could it be that due to the hormonal differences between women and men that women are somehow adversely effected to something else in their environment or even by food. For instance, I have read that heavier girls (due to being overweight) menstruate earlier because some hormone that is triggered by maintaining higher body fat triggers maturation in women.
I have never read that overweight boys s@xually mature faster than women. This could be because there have not been studies on this, I'm not sure. I'm just throwing out possibilities...that maybe men and women are not effected by the same input in tandem.
It could be possible that early maturation leads to less height or some unknown factor in the diet is changing women and not men.
What amazes me is that we are trying to give our best estimates as to why some U.S. populations of African American females are "Shrinking" when in my observation height seems to be inconsistant and hard to predict even under healthy situations.
We don't need to look beyond our own families to see these inconsitancies. In most families the oldest son is usually the tallest and the last son is the shortest. My own grandparents had twelve kids (10 survived) the oldest son is 5'10 1/2, the youngest son is 6'9, that is almost a foot difference between the first born and last born. Even using those growth predictors to predict a child's adult height are off some time.
So I believe height is a bit of a mixed bag, influenced by health, nutrition, & genetic factors yes but there is still chance it can be extreme left or extreme right.
Joined: 07 Feb 2007 {Posts: 1829 } Location: Lookin DC Metro, Feelin Geneva
Posted: Tue 14 Apr 2009 15:43 Post subject:
onlyhuman77 wrote:
What amazes me is that we are trying to give our best estimates as to why some U.S. populations of African American females are "Shrinking" when in my observation height seems to be inconsistant and hard to predict even under healthy situations.
We don't need to look beyond our own families to see these inconsitancies. In most families the oldest son is usually the tallest and the last son is the shortest. My own grandparents had twelve kids (10 survived) the oldest son is 5'10 1/2, the youngest son is 6'9, that is almost a foot difference between the first born and last born. Even using those growth predictors to predict a child's adult height are off some time.
So I believe height is a bit of a mixed bag, influenced by health, nutrition, & genetic factors yes but there is still chance it can be extreme left or extreme right.
Where did you read that most first born sons are the tallest and last born ones are the shortest?
What amazes me is that we are trying to give our best estimates as to why some U.S. populations of African American females are "Shrinking" when in my observation height seems to be inconsistant and hard to predict even under healthy situations.
We don't need to look beyond our own families to see these inconsitancies. In most families the oldest son is usually the tallest and the last son is the shortest. My own grandparents had twelve kids (10 survived) the oldest son is 5'10 1/2, the youngest son is 6'9, that is almost a foot difference between the first born and last born. Even using those growth predictors to predict a child's adult height are off some time.
So I believe height is a bit of a mixed bag, influenced by health, nutrition, & genetic factors yes but there is still chance it can be extreme left or extreme right.
Where did you read that most first born sons are the tallest and last born ones are the shortest?
I never read anything stating most first born sons are the tallest it was an observation, looking at many families, the oldest son is usually the tallest, but there are some families and it is the middle, another set of families and it is the youngest.
I haven't seen much readings on height. I do know that when the pituitary gland becomes overactive, extra tall is the result. If you have any suggested readings, I would love to know. I am a little obsessed with height, since I always wanted to be taller so I could join one of those height clubs.
Joined: 07 Feb 2007 {Posts: 1829 } Location: Lookin DC Metro, Feelin Geneva
Posted: Tue 14 Apr 2009 17:17 Post subject:
onlyhuman77 wrote:
Dragon Horse wrote:
onlyhuman77 wrote:
What amazes me is that we are trying to give our best estimates as to why some U.S. populations of African American females are "Shrinking" when in my observation height seems to be inconsistent and hard to predict even under healthy situations.
We don't need to look beyond our own families to see these inconsitancies. In most families the oldest son is usually the tallest and the last son is the shortest. My own grandparents had twelve kids (10 survived) the oldest son is 5'10 1/2, the youngest son is 6'9, that is almost a foot difference between the first born and last born. Even using those growth predictors to predict a child's adult height are off some time.
So I believe height is a bit of a mixed bag, influenced by health, nutrition, & genetic factors yes but there is still chance it can be extreme left or extreme right.
Where did you read that most first born sons are the tallest and last born ones are the shortest?
I never read anything stating most first born sons are the tallest it was an observation, looking at many families, the oldest son is usually the tallest, but there are some families and it is the middle, another set of families and it is the youngest.
I haven't seen much readings on height. I do know that when the pituitary gland becomes overactive, extra tall is the result. If you have any suggested readings, I would love to know. I am a little obsessed with height, since I always wanted to be taller so I could join one of those height clubs.
The article below is based on a study that claims it is 90% genetic.
Another source I read some time ago said it was 70% genetic, I tried to find it but can't locate it.
A good way, I found some time ago, to measure height, from what I recall is look how many standard deviations your parents are from the average height of their ethnic group (obviously if you come from a more admixed group this won't be as accurate) and then average that.
When I did that, my height was almost exactly where it should be.
I'm 6'2.5", so about 190cm, my wife is 5'4" or 163cm.
My wife is Japanese (born in Japan) where she is more than a standard deviation above normal height, at least I read the average height for a woman there is 5'2". Her sisters are both 5'5", but my wife was the only one who has serious childhood illness, I think this may have cause the variation seen. Her father is not tall, but his sister is (about 5'7"...huge for a Japanese woman) which is about the same height as my father-in-law (her brother)...he also suffered illness as a child though, right after WWII. Her mother is about 5'2" (average for Japanese women today, but in her generation she is slightly tall).
My mother was 5'7", my father 6 foot. I am about where I'm supposed to be, as I'm 6'2.5", which boost in height came from my mother who was much taller than average, as compared to my father who was a little taller (I believe for African Americans...women average 5'4", about the same as white women, and black men are slightly shorter than white males by an inch...at 5'10").
So we often try to figure out how tall our children might be. B
By my estimates, I can expect our daughter to be about 5'5 - 5'7 and our son to be 6'0-6'1?
That assumes some things though. I'm typically black and my wife is typically Asian in our phenotype.
My wife has a torso almost exactly as long as her legs, I'm all legs...so when we sit down I'm only about 2 inches taller than her, when I stand she only comes to my shoulders.
If my we have kids with my legs and her torso they will be quite large indeed.
All of my calculations are assuming both parents had adequate nutrition and no abnormally bad childhood illnesses that can stunt growth.
If spend the first 2 or 3 years of their life in WWII Russia, they might be shorter than they are supposed to be...etc.
Thanks for the article, I wish it would of presented some form of drug that could be used for parents to increase height growth in their children. I am not even married yet, but I don't like to take chances when it comes to height. And because I am planning on adopting internationally (from 3 different countries), it would be truly beneficial if there were drugs available to insure the children reach a certain height.
I plugged you and your wife's info into the height estimator and your estimates match. However, you and your wife's height are almost a foot difference which was the situation with my grandparents.
This is the problem I have, yeah, you and your wife might have a son 6'1 but you could also have a second son 6'7. What exactly happen to produce the 6'7 over his shorter sibling and how can that reaction be repeated for all thee other off spring??
If Black American men are not 'shrinking', and I am assuming they are under the same economical and dietary conditions as their female counterparts, then why would the first assumption be that this is because of a poor diet? And is this same thing happening to women of other races that obesity runs in the family? I was thinking maybe Black American men tend to pro-create more with shorter, curvier women while their White counterparts go for thinner taller women, but then that would lead right back to the other conclusion that Black men should be getting these same short genes as well.
The only hypothesis that would make sense in this situation would be Black immigration from other places like Africa and the West Indies where the people are shorter than the general population here. Or maybe a little combination of all three.
Could it be that due to the hormonal differences between women and men that women are somehow adversely effected to something else in their environment or even by food. For instance, I have read that heavier girls (due to being overweight) menstruate earlier because some hormone that is triggered by maintaining higher body fat triggers maturation in women.
I have never read that overweight boys s@xually mature faster than women. This could be because there have not been studies on this, I'm not sure. I'm just throwing out possibilities...that maybe men and women are not effected by the same input in tandem.
It could be possible that early maturation leads to less height or some unknown factor in the diet is changing women and not men.
"Childhood obesity brings early puberty for girls "
I think they should do more investigation on obese families in other races before they draw too many conclusions. African-American girls normally get their cycles earlier than other races, yet Black women are still on average taller than Hispanic and (especially*) Asian-American women who are presumably given more time to grow because of their later menstruation cycles.
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