Some 1 million adult New Yorkers are obese, but nearly two-thirds of them don't think they are, according to a study released on Tuesday by the city's Department of Health and Mental Hygiene.
Among the obese, who account for about one in five New Yorkers, only 39 percent described themselves as "very overweight," according to the report.
Two percent said they were very underweight, 1 percent said they were slightly underweight, 16 percent said they were just right and 42 percent said they were slightly overweight.
About 2 million more New Yorkers are overweight, the report said, and one in five children in kindergarten is obese.
Only 44 percent of the city's adults are at a healthy weight, and nearly 75 percent say they do not participate in any regular physical activity.
New York City's adult obesity rate was 20 percent in 2003 compared with 23 percent nationwide in 2004. The national average has nearly doubled from 12 percent in 1993, the report said.
Overweight and obese are defined by body mass index, or BMI, which is based on a person's weight, adjusted for height, the department said.
Being obese means having a BMI of 30 or greater, while being overweight means a BMI of more than 25 but less than 30.
A 5-foot, 10-inch (1.78-meter) man weighing 175 pounds (79 kg) would have a BMI of 25.1 and be considered overweight, according to the department. If he weighed 210 pounds (95 kg), he would have a BMI of 30.1 and be obese.
The report was compiled from results of the department's 2002 and 2003 annual telephone surveys of some 10,000 adults.