Added sugar intake from infant formula and complementary foods: A longitudinal investigation and implications for infant weight gain.

Background: Infant formula contains added sugar, although national recommendations state that added sugar should be avoided for infants.

Objectives: Estimate average daily added sugar intake from formula and complementary foods. Examine associations between added sugar intake from formula and complementary foods and weight status among infants in low-income households.

Methods: Between August 2019 and November 2021, mother-infant dyads were recruited from a pediatric clinic primarily serving Medicaid recipients, regardless of feeding type. 24-h feeding recalls were conducted at infant age 6, 9, and 12 months. For directly breast-fed infants, we used the average expected milk volume intake by age. Weight-for-age and weight-for-length z-scores were calculated from health record measurements. Descriptives, bivariate tests, and multilevel linear growth modeling were used.

Results: Most participants (n=234) were African American (39%) or Latino (38%). Infants' daily added sugar intake was on average 7 g from complementary foods and 33 g from formula, with formula being the major source at 6 and 9 months. Daily intake of calories due to added sugar was significantly higher among formula-fed infants compared to breastmilk or sugar-free formula-fed infants (p =.034). For every 10 g of added sugar from formula daily, infants' weight-for-length z-scores increased by an average of 0.060 (SE = 0.018, p = .001).

Conclusions: Formula significantly contributes to added sugar intake among infants compared to complementary foods. A significant positive association between added sugar from formula and infant weight gain suggests the need for regulations limiting added sugar in formula and including added sugar information on formula food labels.