While in prison, in the aftermath of the Seven Years’ War, army pharmacist Antoine-Augustin Parmentier was forced to eat potatoes, which were considered fit only for prison ration and animal feed back then. Parmentier later persuaded the Paris Faculty of Medicine to declare potatoes edible and popularized them in France.
Apart from being a scientist and physician, John Boyd Orr also conducted ground-breaking research on nutrition. The Nobel Peace Prize winner, who was known for his campaigns to end world hunger, had also served the British army and navy as a medical officer. He was later knighted, too.