July 5, 2023 — In the mid-1980s, Louis Aronne strolled into a lab at Rockefeller University where a colleague was breeding mice. “I will never forget what he showed me,” said Aronne, now the director of obesity research and treatment at Weill Cornell Medicine in New York City. “He had a cage with 10 mice, one severely obese and the others normal weight. He took blood from one of the thin mice and gave it to the fat mouse.”
When Aronne returned 3 days later, that obese mouse had turned thin.
It was proof of something Aronne already suspected: Obesity had biological causes and wasn’t just a failure of willpower.