The authors carried out six transverse anthropometric, dietary, and parasitological surveys of 274 schoolchildren (138 boys and 136 girls), aged 10-12 years (in 2001), from the Dongting Lake region in rural South China from 2001 to 2005 to examine intra-population differences in growth. Compared to the Chinese references, the subject children were judged to be retarded in growth at the population level. Comparisons among tertiles classified by the extents of change in weight-for-age Z score from the first to the last survey revealed significant effects of dietary intakes and parasite infections. In particular, there were two observations for the high-tertile boys and girls, whose Z scores of height-for-age, weight-for-age and BMI-for-age in higher ages were similar to, or higher than, the Chinese references. First, their energy intakes were larger than those of mid- and low-tertile boys and girls but were only 80-88% of the recommended dietary allowances for Chinese. Second, they were characterized by high prevalence of Schistosoma japonicum at the first survey but nil from the second survey. In conclusion, there is a high possibility that the children, who are recognized as undernourished at the population level, are able to attain the Chinese standards by increase of energy intake to the level of 10% lower than the recommended allowance for Chinese and eradication of S. japonicum.