In order to maintain his deteriorating health, Kant developed his own rules of life towards the end of his life. One of them was to have only one meal a day.
Kant's lunch could last several hours. It was usually made up of three courses, a wine and a dessert. Kant never ate alone. He would gather between three and nine people to discuss any topic, including forbidden ones. But philosophy and other serious questions were avoided: Kant believed that thinking about complex issues at the dinner table would cause the blood to go to the head rather than the stomach, leading to indigestion.
Kant believed that a good lunch should be accompanied by a conversation structured as follows: 1 — stories, 2 — reasoning, 3 — jokes.