BMI tracking in Mexican American children in relation to maternal BMI.

OBJECTIVE: To assess body mass index (BMI [kg/m2]) tracking over a four-year period in 4- to 8-year-old Mexican American (MA) children and to explore associations between mother and child's BMI. DESIGN: A longitudinal study design was used to assess 138 subjects (69 MA children and 69 MA mothers). Children were classified as normal weight if age- and sex-specific BMI was < 85th percentile and overweight or at-risk for overweight if BMI was > or = 85th percentile. Mothers with a BMI < 25 kg/m2 were classified as normal weight and overweight if BMI was > or = 25 kg/m2. RESULTS: The percentages of children overweight or at-risk for overweight were 34.8%, 36.2%, 40.6% and 39.1% for years 1-4, respectively. A positive correlation was found between the children's BMI status across the four years of the study (r=.90 to .95, P<.001). Furthermore, at-risk for overweight or overweight children in year 1 were highly likely to be overweight or at-risk for overweight in year 4 (adjusted OR: 67.7, 95% CI: 11.7-386.4, P<.001). The correlation coefficients between mothers and daughters' BMIs during the four years were significant (P<.01), but not between mothers and sons' BMIs. CONCLUSION: Overweight or at-risk for overweight status tracks well during childhood and early adolescence among low-income MA children. Sex differences were found concerning associations between mother and their child's BMI.