An information processing system includes an information processing device, a food material stock managing device disposed in a food material storage device, and a meal condition detecting device. The information processing device includes a display device including a display screen, a first communicating circuit that communicates with a portable terminal of a target person, a second communicating circuit that communicates with the food material stock managing device, a third communicating circuit that communicates with the meal condition detecting device, a processor, and a memory storing instructions that cause the information processing device to generate information regarding proposed food to be provided to the target person based on information obtained from the first, second, and third communicating circuits, and display the information regarding the proposed food to be provided to the target person on the display screen of the display device.