title: Ratio of weight to height gain: a useful tool for identifying children at risk of becoming overweight or obese at preschool age.
abstract: OBJECTIVE
  To analyze the usefulness of the weight gain/height gain ratio from birth to two and three years of age as a predictive risk indicator of excess weight at preschool age.
  
  
  METHODS
  The weight and height/length of 409 preschool children at daycare centers were measured according to internationally recommended rules. The weight values and body mass indices of the children were transformed into a z-score per the standard method described by the World Health Organization. The Pearson correlation coefficients (rP) and the linear regressions between the anthropometric parameters and the body mass index z-scores of preschool children were statistically analyzed (alpha = 0.05).
  
  
  RESULTS
  The mean age of the study population was 3.2 years (± 0.3 years). The prevalence of excess weight was 28.8%, and the prevalence of overweight and obesity was 8.8%. The correlation coefficients between the body mass index z-scores of the preschool children and the birth weights or body mass indices at birth were low (0.09 and 0.10, respectively). There was a high correlation coefficient (rP = 0.79) between the mean monthly gain of weight and the body mass index z-score of preschool children. A higher coefficient (rP = 0.93) was observed between the ratio of the mean weight gain per height gain (g/cm) and the preschool children body mass index z-score. The coefficients and their differences were statistically significant.
  
  
  CONCLUSIONS
  Regardless of weight or length at birth, the mean ratio between the weight gain per g/cm of height growth from birth presented a strong correlation with the body mass index of preschool children. These results suggest that this ratio may be a good indicator of the risk of excess weight and obesity in preschool-aged children.
authors.affiliation: Department of Maternal and Child Health, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, SP, Brazil. vivianesimon@usp.br
authors.forename: Viviane G
authors.initials: VG
authors.lastname: Nascimento
authors.forename: Ciro Joao
authors.initials: CJ
authors.lastname: Bertoli
authors.forename: Claudio
authors.initials: C
authors.lastname: Leone
mesh_terms: D000367:Age Factors; D001827:Body Height / Q000502:physiology*; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009752:Nutritional Status; D009765:Obesity / Q000209:etiology; D050177:Overweight / Q000209:etiology*; D012307:Risk Factors; D013997:Time Factors