Diet Beverage Intake during Lactation and Associations with Infant Outcomes in the Infant Feeding Practices Study II

Consumption of diet beverages (DB) containing low-calorie sweeteners (LCS) is widespread in the United States. LCS are ingested by nursing infants upon maternal DB consumption, which may impact infants' weight and health. This study aims to examine cross-sectional associations between infants' LCS exposure via maternal DB intake during lactation and infants' health outcomes. Six hundred and eighty-two mother-infant dyads at three months postpartum, from the Infant Feeding Practices Study II, 2005-2007, were included in the analysis. Maternal DB consumption during lactation was estimated using the serving size and frequency of DB consumption reported on the diet history questionnaire. Infants' LCS exposure was estimated by multiplying maternal DB consumption and breastfeeding intensity. Infant outcomes included weight, weight-for-age and BMI-for-age z-scores, overweight, and gastrointestinal (GI) symptoms including diarrhea, reflux, and vomiting. Associations between infants' LCS exposure and continuous and categorical outcomes were examined using linear and logistic regressions adjusting for confounders, respectively. Forty-three percent of lactating women reported DB consumption. While no significant associations were observed between infants' LCS exposure and BMI-for-age or risk of overweight, infants' LCS exposure was associated with a 2.78-fold increased risk of vomiting (95% confidence interval 1.05-7.34). Potential adverse effects of LCS exposure on GI symptoms require further study, and null findings on infant weight should be interpreted with caution, given the small sample size. Additional research is needed to inform recommendations for or against DB consumption during lactation.