Protein and Carbohydrate Content of Infant Formula Purchased in the United States

Limited independent guidance is provided to parents on how to choose a formula for a healthy term infant. The macronutrient composition of infant formulae has also not been extensively studied. The first goal of the study was to describe the protein and carbohydrate composition of infant formula purchased in the United States. The second goal was to assess the proportion of lactose-reduced and hypoallergenic formulae purchased in relation to the estimated prevalence of medical indications for these formulae.

Fully formula fed American infants (n = 5.7 million) from 2017 through 2019.

Data of purchases of powdered infant formula from all major physical US stores, excluding Costco, from January 1, 2017, through December 31, 2019, were acquired from Information Resources, Inc. Formula intake volumes from the NHANES were used to calculate the average infant consumption for a fully formula-fed infant over 1 year. Global studies were used to estimate the prevalence of cow’s milk protein allergy in the United States. Toddler and preterm infant formula sales were excluded. Protein source, protein hydrolyzation status, and carbohydrate source for all formulas were studied, and then categorized as intact protein dairy; lactose-reduced; lactose-free; and hypoallergenic (extensively hydrolyzed or amino acid).

An average infant was estimated to consume 271 liters (9717 ounces) of formula in the first year of life. Of formula sales, 91.5% were for term infants. The average protein source was 47.4% whey; 46.7% casein; 5.6% soy; and 0.3% amino acid. Nearly 67% of milk and soy formulas purchased had intact protein. Of the milk-based formulas purchased, 26.6% were partially hydrolyzed; 5.2% extensively hydrolyzed; and 0.3% amino acid based. The proportion of hypoallergenic formula purchased (5.5%) exceeded the estimated prevalence of cow’s milk protein allergy in the United States (1.3%). Of all formula purchased, the average carbohydrate source was 52.7% lactose; 42.3% glucose; and 5.0% sucrose. 59% of the formula was lactose-reduced, of which 28.5% was lactose free. There is no medical indication for a nonthickened, intact dairy protein, lactose-reduced formula, although 20% of all formulas purchased were lactose-reduced.

This study is the first to describe the dietary intake of formula-fed infants in the United States. The proportion of hypoallergenic and lactose-reduced formula purchased exceeded the proportion of conditions for which those formulae are medically indicated.

No data exists regarding the long-term effects of glucose or sucrose polymer consumption in infancy from infant formula, though nonlactose sugar usage in formulae can increase the risk of dental caries and altered gut microbiome. The United States does not adhere to international guidelines for marketing breast-milk substitutes. Interestingly, the amount of hypoallergenic formula exceeded the conditions for which they are indicated. The health, socioeconomic, and cultural consequences of these nonstandard formula need further study.