Q: Does breastfeeding affect the risk of childhood obesity? Evidence-based answer: Yes. Even having breastfed during the first year of life is associated with a 15% lower risk of overweight or obesity over the next 2 to 14 years compared with never having breastfed. Breastfeeding exclusively for 6 months is associated with a 30% to 50% reduction in risk (strength of recommendation [SOR]: B, meta-analysis of cohort studies and subsequent cohort studies). However, interventions that increase breastfeeding rates during the first 3 to 6 months of life don't appear to alter body mass index (BMI) at 11 to 12 years of age (SOR: B, randomized clinical trial [RCT]). Introducing complementary (solid) foods before 3 months is associated with a 30% greater risk of childhood obesity than later introduction; starting solid foods after 4 months isn't linked to increased obesity. High caloric density of complementary feedings may be associated with greater childhood obesity (SOR: C, systematic reviews of heterogeneous cohort studies). Scheduled feeding doubles the risk of rapid infant weight gain compared with on-demand feeding, although it's unclear whether a direct relationship exists between rapid infant weight gain and childhood obesity (SOR: B, cohort study)
