Soy Protein-Based Infant Formula Feeding Association with Adolescent Growth, Body Composition, Cardiometabolic Health, and Pubertal Development in Comparison with Cow's Milk-Based Infant Formula and Human Milk Feeding

Abstract

Background: Although ∼12% of infants in the United States are fed soy protein-based infant formulas (SF), data on the long-term health effects compared with cow's milk-based infant formulas (MF) and human milk (HM) remain limited.

Objectives: This study aims to assess whether SF feeding during infancy influences adolescent growth, adiposity, dietary intake, metabolic health, or pubertal development compared with MF or HM feeding during infancy.

Methods: In the Beginnings follow-up study, 190 participants (SF = 52, HM = 76, MF = 62) were assessed at age 14 y for anthropometry, body composition, dietary intake, cardiometabolic biomarkers, pubertal stage, and reproductive organ volumes and characteristics. Statistical analyses were performed using R (version 4.4.2), and included generalized linear regression models adjusted for age, sex, race/ethnicity, mother's education, and birth characteristics.

Results: At 14.10 ± 0.26 (13.47-14.96) y, adjusted models showed that adolescents who were fed SF as infants had similar body weight, BMI-for-age z-score, fat mass index, abdominal adiposity (visceral and subcutaneous adipose tissue areas), and waist circumference compared with participants fed MF and HM as infants. Energy intake, macronutrient intakes, and diet quality (Healthy Eating Index-2020) were comparable across groups, except for a lower fat intake (%kcal) for participants fed SF and HM as infants compared with MF. There were no significant differences between the groups in blood pressure, glucose metabolism, lipid profile, inflammatory biomarkers, pubertal stage, age of menarche and reproductive organ sizes and characteristics at age 14 y. The prevalence of cardiometabolic risk factors was significantly higher in participants who were fed MF (8.1%) compared with SF (3.8%) and HM (0.0%) as infants.

Conclusions: SF feeding during infancy was associated with similar growth, body composition, cardiometabolic health and puberty outcomes at age 14 y as MF and HM feeding. In adjusted models, HM feeding was protective against adolescent adiposity compared with MF feeding. This study was registered at www.

Clinicaltrials: gov as NCT03108014.

Keywords: adolescent; body composition; cardiometabolic risk factors; infant feeding; soy infant formula.