Studies have shown that babies born small are at increased risk for type 2 diabetes, obesity, hypertension, and cardiovascular disease. Most studies have focused on infants who were small for gestational age and born at term or premature. Post-term birth is relatively common and it has been speculated that post-term gestation may produce a suboptimal environment for the fetus. Life course risks for chronic disease have not been extensively studied for children who were born post-term. In this issue of The Journal, Beltrand et al evaluated whether post-term birth is associated with obesity in adolescents. Their results show that even though body mass index (BMI) is similar for term and post-term infants until age 2 years, after that they start to diverge, with post-term infants having significantly greater BMI and an increasing separation in BMI, especially after age 12 years. These results suggest that pediatricians should counsel parents of infants born post-term on diet, physical activity, and other lifestyle factors. Article page 769▶