Nearly 36 percent of black Americans are obese - much more than other major racial or ethnic groups - and that gap exists in most states, a new federal study finds.

About 29 percent of Hispanics and 24 percent of whites are obese, the Centers for Disease Control and Prevention reported Thursday. Overall, about 26 percent of U.S. adults are obese.

Racial differences in obesity rates have been reported before, and health officials were not surprised to see larger proportions of blacks tipping the scales.

But the new CDC report is the first to look at the gap state-by-state, finding blacks had significantly higher obesity rates in 21 states and somewhat higher rates in many others.

Experts believe there are several reasons for the differences. People with lower incomes often have less access to medical care, exercise facilities and more expensive, healthier food. In many places, minorities are disproportionately poor.

"Poverty is a very strong driver of obesity," said Kelly Brownell, director of Yale University's Rudd Center for Food Policy and Obesity.

Attitudes about weight also are believed to be a factor, said Dr. Liping Pan, a CDC epidemiologist. Researchers cited a 2008 study that found black and Hispanic women had significantly lower odds of being dissatisfied with their body size than white women.

"Black and Hispanics are more accepting of high weight," Pan said, adding that heavy people who are satisfied with their size are not likely to diet or exercise.

However, it could be that over time as people struggle with poverty and environment "they come to accept the higher weights," Brownell said.

Obesity is based on the body mass index, a calculation using height and weight. A 5-foot-7-inch adult who weighs 190 pounds would have a BMI of 30, which is considered the threshold for obesity.

The data comes from a national telephone survey of more than 1 million Americans over the years 2006 through 2008.

For blacks, the highest obesity rate was in Maine, where 45 percent were obese. Tennessee was the state where Hispanic obesity was most common. And West Virginia was the fattest state for whites.

But generally, obesity was most common for both blacks and whites in the South and Midwest.

The study also broke down the groups by gender, and found black women were the heaviest, with 39 percent counted as obese. Black men were next, at 32 percent, then Hispanic women, 29 percent, Hispanic men, 28 percent, white men, 25 percent and white women, 22 percent.

一项最新的联邦研究发现，近百分之三十六的美国黑人是肥胖者，这远远超过其他主要种族或民族群体，而且这种差别存在于大多数国家中。

据疾病控制和预防中心周四报道，约百分之二十九的西班牙人和百分之二十四的白种人是肥胖者。总体而言，约百分之二十六的美国成年人是肥胖者。

在肥胖率的种族差别被报道以前，卫生部门官员并没有因为黑人在肥胖症中占较大比例而感到惊讶。

但是，新的疾病预防控制中心报告是第一次看到州与州之间的差别，在21个州发现了黑人的肥胖率极高，在其他州的比率也有点高。

专家认为造成这种差别的原因有很多。收入较低的人往往很难获得医疗保健，运动设施以及比较昂贵健康的食品。在很多地方，一部分人处于不同程度的贫穷状态。

贫穷对造成肥胖具有极大的推动作用。"耶鲁大学食品政策与肥胖研究中心主任凯利布劳内尔认为。

对体重的态度也被认为是其中的一个因素，DC的流行病学家潘力平博士表示。研究人员列举了2008年的研究，发现黑人和西班牙裔妇女对她们身材的不满意程度要比白人妇女低很多。

"黑色和西班牙人更接受高体重， "潘说，对自己体重感到满意的胖人也不大可能节制饮食或经常运动。

然而，也许随着时间的推移，人们不断与贫穷和环境做斗争，"他们也许会开始接受较高的体重， "布劳内尔说。

肥胖是根据身体雷竞技百科 指数，用身高和体重计算出来的结果。 一个5英尺7英寸高体重一百九十磅的成年人体重指数为30 ,这个指数被当作是他肥胖的门槛。

这个数据来自于一个全国性电话调查，从2006年到2008年调查了超过一百万的美国人。

黑人肥胖率最高的是缅因州，那里百分之四十五的人是肥胖者。在田纳西州西班牙肥胖者是最常见的。西弗吉尼亚州是白人肥胖者最多的州。

但通常，不管是黑人还是白人，肥胖者在南部和中西部最常见到。

这项研究还根据性别进行了分组，发现黑人妇女是最重的，百分之三十九的人是肥胖者。接着是黑人男子，百分之三十二，然后是西班牙裔妇女，百分之二十九，西班牙裔男子，百分之二十八，白人男子，百分之二十五，白人妇女，百分之二十二。