[A national survey on growth of children under 7 years of age in nine cities of China, 2005].
OBJECTIVE
To reevaluate the normal physical growth of Chinese children and for a better understanding of its general trend within the recent 30 years and to provide the child growth reference data of Chinese children from 0 to 7 years of age.


METHODS
Random cluster sampling was used. The subjects consisted of 138,775 healthy children under the age of 7 years from urban and rural areas of nine cities (Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Fuzhou, Guangzhou and Kunming). All the children were classified into 22 age groups. The sample size was at least 100-150 for each sex-age group in each area (urban/rural) of each city. Weight, height (supine length if under 3 years), sitting height (crown-rump under 3 years), chest circumference and head circumference were measured for all children.


RESULTS
Compared with the results obtained in 1995, the mean weight, height and sitting height significantly increased. The increment increased with chronological age. For example, at ages 6-7 years, the weight increments in the past 10 years were: urban boys and girls 1.54 kg and 1.19 kg, rural boys and girls 1.46 kg and 1.37 kg; the height increments were: urban boys and girls 2.1 cm and 1.8 cm, rural boys and girls 3.1 cm and 3.0 cm. The head and chest circumference in most age groups were slightly improved. The urban-rural difference and regional difference in growth were still significant. But the urban-rural difference in height has become smaller, as the increase has been greater in rural areas. Compared with the results of four previous studies conducted from 1975 to 2005, the results of the present survey showed that the weights and heights of Chinese children were still in the trend of accelerative growth in the past 30 years. At ages 6-7 years, the weight and height increments of urban boys and girls were 3.26 kg, 2.88 kg, 5.3 cm and 5.0 cm; and those of rural boys and girls were 2.68 kg, 2.58 kg, 7.6 cm and 7.5 cm, respectively, within the 30 years. Compared with the increments of each 10 years, the increasing rates were higher in the second decade than in the first decade; and in the third decade than in the second decade.


CONCLUSIONS
The condition of growth and nutrition of Chinese children has been much improved than that seen ten years ago and the secular trend is still continuing at an accelerated growth stage. The weights and heights of Chinese children in nine cities have reached or surpassed that of the new WHO child growth standards.
D044466:Asian People; D001827:Body Height / Q000502:physiology*; D001835:Body Weight / Q000502:physiology*; D002648:Child; D002657:Child Development / Q000502:physiology*; D002681:China; D002947:Cities; D003625:Data Collection; D005260:Female; D006801:Humans; D008297:Male; D012424:Rural Population / Q000639:trends*; D014505:Urban Population