Background: Neonatal anoxia may cause neurological injuries, behavioral alterations and changes in somatic growth. Somatic developmental changes suggest a possible effect of anoxia on energy metabolism and/or feeding behavior. Short-term effects of oxygen deficit on energy homeostasis have been described. In contrast, just a few studies report long-term effects. This study investigated the effects of neonatal anoxia on energy metabolism and somatic development at adulthood of males and females Wistar rats. Method: Male (m) and female (f) rats were exposed, on postnatal day 2 (P2), to either 25-min of Anoxia or Control treatment. At P34 part of the subjects of each group was fasted for 18 h, refeed for 1 h and then perfused 30 min later, at P35; the remaining subjects were submitted to these treatments at P94 and perfused at P95. Therefore, there were 8 groups: AmP35, AmP95, AfP35, AfP95, CmP35, CmP95, CfP35 and CfP95. For subjects perfused at P95, body weight and food intake were recorded up to P90. For subjects perfused at P35 and P95, glycemia, leptin and insulin were assessed after fasting and refeed. After perfusion the encephalon and pancreas were collected for Fos immunohistochemistry and Hematoxylin-Eosin stain analyses. Results: Even though neonatal anoxia did not interfere with regular food intake, it reduced body weight gain along growing in both male and female subjects as compared to the corresponding controls. At P35 neonatal anoxia decreased post-prandial glycemia and increased insulin. While at P95 neonatal anoxia altered the pancreatic histomorphology and increased post-fasting weight loss, decreasing leptin, insulin and glycemia secretion, as well Fos immunoreactivity (IR) in ARC. Conclusion: Neonatal anoxia impairs long-term energy metabolism and somatic development in Wistar rats, with differences related to sex and age.