To allow a caloric intake to be simply and accurately estimated.

A caloric intake estimating process includes the following sequential steps of: imaging an image by sequentially switching transmission wavelengths by an etalon while emitting light from a light source, a step S315; extracting a portion of a food product from the image when a user starts a meal and lifts a morsel of the food product to his or her mouth, a step S330, YES; estimating a volume of the food product as the portion extracted on the basis of a visible light image, a step S340; obtaining mass of the food product, a step S350; estimating a caloric value per the mass of the food product from an infrared absorption spectrum, a step S360; determining whether or not the caloric value of the food product in the mouth is reduced by comparing with a result of a step S370 having been previously executed, a step S380; and adding the caloric value to a total caloric intake as a caloric intake, a step S390, in a case where the caloric value is determined to be reduced, the step S380, YES.