Evaluating the effect of energy-dense foods consumption on preschool children's body mass index: a prospective analysis from 2 to 4 years of age

Purpose The aim of this study was to study the association between the consumption of energy-dense foods at 2 years and body mass index (BMI) at 4 years, using a cross-lagged panel design. Methods The present study included 589 children evaluated at 2 and 4 years of age, as part of the birth cohort generation XXI. Information was obtained by face-to-face interviews. Consumption of energy-dense foods (salty snacks, soft drinks, cakes, and sweets) was measured using a food frequency questionnaire. Children's weight and height were measured by standard procedures, and BMI standard deviation scores (BMI z-scores) were calculated according to the World Health Organization. Linear regression and cross-lagged panel design models were fitted to estimate the associations between the consumption of energy-dense foods and BMI z-scores (controlled for maternal age, education and prepregnancy BMI, and children's exact age at 2 years). Results The consumption of energy-dense foods at 2 years was significantly associated with their consumption at 4 years (beta = 0.522, 95 % CI 0.432-0.612). Children's BMI z-scores at 2 years were associated with posterior BMI z-scores (beta = 0.747, 95 % CI 0.688-0.806). In the cross-lagged analysis, consumption of energy-dense foods at 2 years had no effect on subsequent BMI z-scores (beta = -0.030, 95 % CI -0.095 to 0.035) and BMI z-scores at 2 years were not significantly associated with the consumption of energy-dense foods at 4 years (beta = -0.012, 95 % CI -0.086 to 0.062). Conclusion Consumption of energy-dense foods and BMI tracked over time, but the consumption of energy-dense foods at 2 years was not associated with BMI z-scores at 4 years.