Added sugars mediate the relation between pre-pregnancy BMI and infant rapid weight gain: a preliminary study.

Background: Parental obesity is linked to offspring obesity, though little research has explored factors that might influence this relationship during the complementary feeding period. This study investigated whether infant intakes of added sugars mediate the relationship between a mother's pre-pregnancy body mass index (BMI) and infant rapid weight gain (defined as upward weight-for-age percentile crossing).

Methods: This study was of a cross-sectional design. Anthropometrics for 141 mother-infant dyads (mean age [standard deviation]: 32.6 [4.4] year for mothers, 11.9 [1.9] months for infants) were obtained. Data from three 24-h recalls pertaining to the infants' diets were collected and analyzed. Pearson product-moment correlations and multivariable regressions assessed bivariate relationships between pre-pregnancy BMI, infant added sugar intakes and upward weight-for-age percentile crossing. Mediation models evaluated the effects of added sugars and breastfeeding duration.

Results: Pre-pregnancy BMI correlated positively with infants' added sugar intakes (r = 0.230, p = 0.006). Added sugar intakes mediated the impact of pre-pregnancy BMI on upward weight-for-age percentile crossing (indirect effect = 0.007, 95% CI = 0.0001, 0.0197, indirect/total effect ratio = 0.280). Breastfeeding duration also moderated the relationship, with infants who were breastfed for a shorter duration experiencing a greater mediating effect (indirect effect = 0.010, 95% CI = 0.0014, 0.0277, indirect/direct effect ratio = 0.7368).

Conclusions: Mothers who were overweight or obese prior to pregnancy were significantly more likely to give their infants foods and beverages with added sugars, and this practice was found to mediate the relationship between maternal and infant obesity. Breastfeeding duration moderated the mediating effect of added sugars between pre-pregnancy BMI and infant rapid weight gain.