In the early 90’s, he was a fellow at the Division of Pediatric Gastroenterology and Nutrition at The Children’s Hospital of Philadelphia, and returned to Israel to head the Department of Nutrition at the Israel Ministry of Health.Dr. Shamir's current research areas include exploring the effects of oral insulin supplementation on the intestine, pediatric nutrition and childhood hyperlipidemia, celiac disease and examining the role of paraoxonases in the intestine.