Age at Introduction of Solid Foods Does Not Appear to Affect Risk of Obesity at 3 Years in Exclusively Breastfed Infants

Current guidelines from the World Health Organization and the American Academy of Pediatrics recommend delaying the introduction of solid foods until the age of 4-6 months, although the scientific basis for this recommendation is limited and derived mostly from studies relating to atopic disorders. A recent cohort study evaluated the effects of starting solid foods at different ages on the risk of obesity (body mass index [BMI] ≥ 95th percentile) at 3 years of age. A total of 847 children were followed from before birth and assessed for feeding practices and BMI. Children were stratified by history of breastfeeding and age at the introduction of solid foods. In analysis of 568 children who were exclusively breastfed until they were given solid foods, there were no significant differences in the rates of obesity at 3 years old regardless of whether solid foods were started before 4 months, at 4-5 months, or at 6 months (7% for each group) (level 2 [mid-level] evidence). However, among children who were formula-fed (either never breastfed or completely weaned before 4 months), obesity rates at 3 years did appear to vary with age of solid food introduction: 25% for those starting solid foods before 4 months, 5% at 4-5 months, and 16% at > 6 months. Compared to children in this subgroup who started solid foods at 4-5 months, the obesity risk at 3 years was significantly higher for children starting at < 4 months (odds ratio 6.3, p < 0.001), and there was a trend toward increased risk in children starting after 6 months (p = 0.06) (Pediatrics 2011 Mar;127(3):e544). For more information, see the Nutrition (pediatric preventive care) topic in DynaMed.