In order to provide a liquid food that can be used in drip treatments and has a more physiologically desirable viscosity than a liquid food with extremely low viscosity, a nutritional composition is provided by using water-absorbing dietary fiber and starch that has not been subjected to gelatinization. The viscosity of the nutritional composition is maintained during a simple manufacturing process involving steps from preparing raw materials to filling containers with the nutritional composition, and said nutritional composition has a viscosity that is suitable for flexible containers with an outlet used for intubation administration by drip, or oral administration, after being treated by heat.