***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The evaluation of  child growth trajectories  and the interventions design ed to improve child health are highly dependent on the growth charts used . The U.S. CDC and the WHO , in May 2000 and April 2006 , respectively , released new growth charts to replace the 1977 NCHS reference . The WHO charts are based for the first time on a prescriptive , prospect i ve , international sample of infants selected to represent optimum growth . This article compares the WHO and CDC curves and evaluates the growth performance of healthy breast-fed infants  according to both . As expected , there are important differences between the WHO and CDC charts that vary by age group , growth indicator , and specific Z-score curve . Differences are particularly important during infancy , which is likely due to differences in study design and characteristics of the sample , such as type of feeding . Overall , the CDC charts reflect a heavier , and somewhat shorter , sample than the WHO sample . This results in lower rates of undernutrition ( except during the first 6 mo of life ) and higher rates of overweight and obesity when based on the WHO st and ards . Healthy breast-fed infants track along the WHO st and ard 's weight-for-age mean Z-score while appearing to falter on the CDC chart from 2 mo onwards . Shorter measurement intervals in the WHO st and ards result in a better tool for monitoring the rapid and changing rate of growth in early infancy . Their adoption would have important implication s for the assessment of lactation performance and the adequacy of infant feeding and would bring coherence between the tools used to assess growth and U.S. national guidelines that recommend breast-feeding as the optimal source of nutrition during infancy 
    Output:
    
Discussion This will be the first systematic review of studies to establish the change in BMI required to improve metabolic health status in obese children and adolescents .