BMI Not So Good For Asians

A couple weeks ago Linda Carroll of MSNBC reported on the growing doubt surrounding the Body Mass Index. The BMI is commonly used to determine if a person is of healthy bodyweight, but as Carrol explained it has its problems:
BMI can be way off, especially when it comes to assessing a particular individual. The commonly used measure can give a skewed result not only for fit body builders who come out with a high number because of the extra weight associated with muscle, but also for the elderly, who tend to have scores that underestimate obesity because they have so much less muscle.
In response Dr. Fuhrman provided his method of determining whether or not someone has a healthy bodyweight:
I just take a pinch near the umbilicus and squeeze it lightly between two fingers and measure the distance between the fingers.
Well, we might need to start pinching Asians. Because according to a new report by Malcolm Burgess of AFP the Body Mass Index often misdiagnoses them:
The standard way to define obesity uses the body-mass index -- a measure of weight divided by height -- but weight-related ill health appeared in East and South Asians at a lower cut-off point than in Caucasians, they said.


World Health Organisation guidelines say a BMI of 25 is healthy, more than 25 is overweight and more than 30 obese.

Taiwanese academic Pan Wen-Harn told the 10th International Congress on Obesity in Sydney that such criteria missed a large number of people in Asia.

Chinese, Japanese, Koreans and Indians experienced metabolic risks such as hypertension and diabetes at a much lower threshold, she said.

"You don't have to wait until you get a BMI of over 25 -- even at 23 or 24 a substantial number of people have those diseases," she said.
Burgess cites the spread of the western diet and lifestyle as a reason why Asians are getting heftier:
Indian researcher Naval Vikram agreed that while the westernisation of the Indian diet and less physical exercise contributed to metabolic disorders, most blame lay with genetic make-up.


Indians tended to have high body fat, a low body-mass index, high abdominal fat and a low waist circumference, he said.

They suffered hypertension and lipid problems at a BMI of 22 or 23 -- much lower than other ethic groups, he said.

"If we use international definitions we will be missing about 15 to 20 percent of people whom we would be able to identify with a lower cut-off point. That's a substantially large proportion, taking the population of India," he said.
This story harks at the same issues illustrated in the series of reports by The New York Times investigating the diabetes epidemic in New York City. Here’s an excerpt from N.R. Kleinfield’s report:
One in three children born in the United States five years ago are expected to become diabetic in their lifetimes, according to a projection by the Centers for Disease Control and Prevention. The forecast is even bleaker for Latinos: one in every two.


New York, perhaps more than any other big city, harbors all the ingredients for a continued epidemic. It has large numbers of the poor and obese, who are at higher risk. It has a growing population of Latinos, who get the disease in disproportionate numbers, and of Asians, who can develop it at much lower weights than people of other races.
Fellow New York Times reporter Marc Santora offers up more evidence that the Western way of eating isn’t well-suited for Asians:
Asian children in New York are obese, more than twice the rate among their parents. And they say there is mounting evidence - including soaring diabetes rates in major cities in China, and in other countries with Chinese immigrants - that New York will soon experience a similar explosion as more Asians arrive and have their first encounters with Western ways.


The clash of cultures is vividly apparent in Flushing, one of the city's new Chinatowns. On streets like Roosevelt Avenue, older immigrants still throng traditional Asian markets, with their signs in Chinese, and dine at noodle shops where windows fog with steam. Their children, however, are increasingly lured by fast food. Along a 100-yard strip of storefronts are a McDonald's, a Burger King, a Taco Bell, a Pizza Hut, and a Joe's Best Burger.

Even in China, the number of obese people has tripled since 1992 to 90 million, as Western food has become popular and prosperity has made it possible to eat more. The World Health Organization has warned that Asia faces a "tsunami" of diabetes in the coming decade, and health officials have assailed the Chinese government for its tepid response to the crisis.
It really seems like the problem extends beyond the shortcomings of the BMI. In Eat to Live Dr. Fuhrman explains Asians, in particular the Chinese who traditionally eat a very healthy plant-based diet, are biologically reeling from the effects of the Western lifestyle:
The Chinese [living in China], who on the average consume more calories, are thinner than Americans.1 In China the calorie intake per kilogram of body weight is 30 percent higher than in the United States. The Chinese eat about 270 more calories per day than Americans, yet they are invariably thin. Exercise cannot fully explain this difference, as researchers discovered the same thing with Chinese office workers as well.


This may be because calories from carbohydrates are not as likely to increase body fat as the same number of calories from high-fat foods such as oils and meats, which make up such a high proportion of the American diet. The data suggests that when a very low fat diet is consumed (15 percent average dietary fat in rural China), as compared to the typical Western diet (30-45 percent of calories from fat), more calories are burned to convert carbohydrate in fat, so the body cannot store fat easily.

The modern American diet receives about 37 percent of its calories from fat, with lots of sugar and refined carbohydrates. The combination of high fat and high sugar is a metabolic disaster that causes weight gain, independent of the number of calories.
1. Campbell, T.C., and J. Chen. 1994. Diet and chronic degenerative diseases, in Western diseases: their dietary prevention and reversibility. Edited by M.J. Temple and D.P. Burkitt. Totowa, N.J.: Humana Press, pp. 67-119.
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nivrittichandra - September 16, 2006 4:11 AM

can u please post me some information(articles from journals if possible)
for the eitiology of a high body fat percentage in asians, despite a normal BMI

benny - August 1, 2007 11:32 PM

True indians are not healthy with high body fat.but it's changing rapidly we are no doubt caching up with rest of world.

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