To the casual observer, Asian Americans may appear immune to the obesity epidemic plaguing whites, African Americans, and Hispanics at a national obesity rate of 35 percent. With relatively low body weights, only 11 percent of Asian Americans are considered obese.

However, this growing population of Americans — set to grow from five percent to nine percent by 2042 — may simply be more susceptible to obesity-related health effects at lower weights, with many embodying the concept of “skinny fat” person.

The U.S. Centers for Disease Control and Prevention (CDC), for the first time, considered Asian Americans along with other racial groups in the National Health and Nutrition Examination survey, given the growing population of Asians in cities along the West Coast, Chicago, and along the Eastern Seaboard. The federal government defines “Asian,” a heterogeneous racial group, as people with ancestral heritage from the Far East, Southeast Asia, or the Indian subcontinent, including Cambodia, China, India, Japan, Korea, Malaysia, Pakistan, the Philippine Islands, Thailand, and Vietnam.

Among findings in the study, investigators say body mass index (BMI) may serve as a poor indicator of health for many Asians, as some may develop metabolic syndrome, diabetes, and cardiovascular disease at much lower weights relative to others.

“It looks as if we don’t have a problem, but it’s a huge problem,” Karen Kim, a professor of medicine at the University of Chicago, told NBC News. “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.”

Using the oft-criticized BMI, a standard calculation of body fat comparing height to weight, health authorities generally consider a rating of 25 to be overweight, 30 or higher to be obese. According to the study, only 10.8 percent of Asian Americans scored 30 or higher, compared to one-third of whites, 42 percent of Hispanics, and nearly half of African Americans.

“When you’ve got obesity rates at 30 to 40 to 50 percent in other population groups, it doesn’t look like anything,” Marjorie Kagawa Singer, a professor in the school of public health and Asian-American studies at the University of California, Los Angeles, told NBC News.

Yet, Asian Americans experience an increased risk for diabetes at a relatively lower BMI of only 24, according to the American Diabetes Association. Moreover, the risk of cardiovascular disease, more prevalent among those who are overweight or obese, rises for Asian Americans with BMIs of 19 or 20, a body mass index that might seem a bit “light” for other racial groups in America.

Some experts say physiological differences apparent to the naked eye may account for much of the difference in susceptibility to obesity-related illnesses. Although phenotypic body types may range greatly among Asians, a broad racial category encompassing some two-thirds of the world population, “apple-shaped” bodies are more common among people with Asian descent. They’re also more likely to pack excess fat between and around the organs, with abdominal fat linked to obesity-related health risks such as heart disease, type 2 diabetes, and inflammatory diseases.

“It’s true that you really don’t see Asians that are morbidly obese, but you don’t have to be morbidly obese to have some of these complications,” Kim said.

As a better barometer of health, Asian Americans — and others — should consider waist circumference and fat distribution measurements rather than BMI, which more highly correlate with metabolic syndrome, for example.

Moreover, specific subsets of the broad racial category of “Asian” should consider themselves more distinct when thinking about health, Kim said. Whereas Filipinos are 70 percent more likely to be obese than other Asian Americans, adults with Korean or Vietnamese heritage are far more likely to have the opposite issue, with one in 10 underweight, according to the CDC.

Kathy K. Chin, president and CEO of the Asian & Pacific Islander American Health Forum, says Asian Americans should eschew the “model minority” racial stereotype, which holds that members of this population not only achieve higher than average economic and educational statuses but also remain immune to health effects associated with fatter Americans.

“'I’m skinny, and I’m Asian, I should be fine — I don’t have to worry about obesity and diabetes’” is the attitude held by many Asians across the country, Scott Chan, program director for the Asian Pacific Islander Obesity Prevention Alliance, told NBC News. “We buy into that.” So much so, Chan said, he has trouble convincing members of his own family to take seriously the stealthy risk of diabetes and other obesity-related ailments, given deceptively lower body weights and apparent good health.