A recent study has claimed that, “among formula-fed infants or infants weaned before the age of 4 months, introduction of solid foods before the age of 4 months was associated with increased odds of obesity at age 3 years.” Susanna Huh, et al., “Timing of Solid Food Introduction and Risk of Obesity in Preschool-Aged Children,” Pediatrics, February 2011. Harvard researchers apparently followed 847 children enrolled in a pre-birth cohort study known as Project Vida, using “separate logistic regression models for infants who were breastfed for at least 4 months (‘breastfed’) and infants who were never breastfed or stopped breastfeeding before the age of four months (‘formulafed’), adjusting for child and maternal characteristics.” The study findings apparently indicated that, among the formula-fed infants only, “introduction of solid foods before 4 months was associated with a six-fold increase in odds of obesity at age 3 years.”

“One possible reason why we saw an association among formula-fed but not breastfed infants is that formula-fed infants may increase their energy intake when solids are introduced. Breastfeeding may promote self-regulation of an infant’s energy intake, and the mother may learn to recognize her infant’s hunger and satiety cues,” speculated the study authors, who noted that their results supported the American Academy of Pediatrics’ recommendations to introduce solids between 4 and 6 months of age. See The Wall Street Journal, February 7, 2011.