WEDNESDAY, July 15, 2009 (HealthDay News) -- The number of underweight children aged 2 to 19 in the United States decreased from 5.1 percent in 1971-1974 to 3.3 percent in 2003-2006, says a U.S. government study.
Being underweight can be caused by malnutrition or underlying health problems.
Researchers at the U.S. Centers for Disease Control and Prevention's National Center for Health Statistics analyzed results from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) and compared them with results from the 1970s. They found that underweight decreased from 5.8 percent to 2.8 percent among children aged 2 to 5, from 5.3 percent to 2.7 percent among children aged 6 to 11, and from 4.7 percent to 3.8 percent among those aged 12 to 19.
Surveys before 1971 didn't include children aged 2 to 5, the authors of the report noted.
The NHANES participants underwent a household interview and a physical examination that included weight and height measurements taken by trained health technicians using standardized measuring procedures and equipment.
Children with body-mass index (BMI) values below the 5th percentile of the sex-specific BMI-for-age growth charts are classified as underweight.
The Nemours Foundation has more about children's weight.