Melissa Dahl, NBC News, October 17, 2013
At first glance, it seems like most Asian-Americans pretty much have this whole obesity thing under control, by the looks of new national statistics. An estimated 11 percent of adult Americans of Asian descent are considered obese. Compare that to the nation’s obesity average as a whole, which stands steady at about 35 percent.
Why are Asian-Americans so much thinner? The answer may not be obvious, some experts say.
“It looks as if we don’t have a problem. But it’s a huge problem,” says Dr. Karen Kim, a professor of medicine at the University of Chicago. “There are huge differences where weight does not adequately reflect the realities of complications from being overweight. For Asians, you do not have to be overweight to get the complications for obesity.”
The NHANES uses body mass index, or BMI, to judge whether a person is overweight or obese. BMI is a standard way of calculating body fat using a person’s height and weight: A BMI above 25 is considered overweight, and a BMI of 30 or higher is considered obese. According to this new data, just 10.8 percent of Asians in America are considered obese, a slim percentage when compared with the 33 percent of whites, 42 percent of Hispanics and 48 percent of blacks with a BMI of 30 or higher.
But studies have suggested that BMI is a poor indicator of the consequences of obesity in Asians, many of whom show the health risks that come along with obesity — things like metabolic syndrome, diabetes and cardiovascular disease — at a much lower BMI.
One example: Asian-Americans are at increased risk for diabetes at a BMI of 24, according to the American Diabetes Association. And, Kim says, the risk for cardiovascular disease, another illness normally associated with being overweight or obese, can start in normal-weight Asians who have a BMI of just 19 or 20.
Basically, it’s that concept of being “skinny fat”: Physiologically, people of Asian descent are either more likely to be “apple-shaped,” or their excess fat may be packed between and around the organs. Abdominal, or visceral, fat has been linked to obesity-related health risks like heart disease, type 2 diabetes and inflammatory diseases.
Instead of relying on BMI, Kim and other health experts say that a more helpful benchmark for measuring obesity–in any population–may be to consider waist circumference and fat distribution, both of which are highly correlated with metabolic syndrome.
The other big issue to note: Looking at “Asian-Americans” as a whole is so broad that it’s almost meaningless, says Kathy Ko Chin, president and CEO of the Asian & Pacific Islander American Health Forum. “If it’s all clustered together as ‘Asian’ — then that would really mask rates of obesity for specific populations.”
Filipino adults are 70 percent more likely to be obese than the rest of the Asian-American population — but about one in 10 Vietnamese and Korean adults is underweight, according to a large 2008 report.