[Research on the growth references of height, weight and body mass index for children under 7 years old].

OBJECTIVE

To understand the varying features and the trend of length/height-for-age, weight-for-age and body mass index(BMI)-for-age of children under six years old in Ningbo city, Zhejiang province.

METHODS

By random clustered sampling, 64 038 healthy children under six years old in Ningbo were chosen and their length/height and weight measured. Means, standard deviation and percentiles of length/height-for-age, weight-for-age and BMI were calculated by SAS systems. Results of this study were compared with growth standards from WHO 2006 and nine urban areas of China, in 2005.

RESULTS

Data from our study showed that the annual growth rates were basically the same in boys and girls. All these indicators increased along with age but the younger the age, the faster the growth rate appeared. There were notable differences seen between genders and urban-rural distribution. BMIs were also varied with age and sex. BMI reached peak between 4 to 6 months, then dropped slowly when age increased.

CONCLUSION

The means of length/height-for-age, weight-for-age in Ningbo city had exceeded the WHO standards, and the growth by year under six year-olds in Ningbo was close to the data from nine urban areas of China in 2005.