David Morris Kipnis (May 23, 1927 – February 5, 2014) was an American endocrinologist and medical researcher at Washington University in St. Louis.
He first became interested in medicine as a young child when he would carry his local pediatrician's medical bag on house calls.
After graduating from Johns Hopkins University at the age of 18, he was considered too young to enroll in medical school, so he joined the U.S. Army at Fort Leonard Wood before returning to Maryland.
He discovered the "incretin effect"—demonstrating that consuming sugar and other carbohydrates by mouth leads the gut to release hormones that promote the release of insulin—which was the foundation for a new class of drugs to treat diabetes.
[1] He also studied the regulation of insulin release by the pancreas and the transport mechanisms of glucose and amino acids in the body.