A concentrated liquid food, comprising: a polysaccharide which is one or more members selected from the group consisting of pectins, and alginic acids or salts thereof that becomes gelated or thickened by combining with calcium; 0.005 mass% to 0.25 mass% on a calcium basis of a water-soluble calcium source having a solubility of 0.1 g/100 mL or more at 20.0°C under a pH of 7.0; 0.10 mass% to 2.0 mass% of at least one member selected from the group consisting of trisodium citrate and tripotassium citrate; a protein having emulsifiability; and 0.2 mass% to 5.0 mass% of a soybean hemicellulose, wherein the concentrated liquid food has a viscosity of 250 mPa·s or less before contact with a simulated gastric fluid, and has a viscosity of 1,500 mPa·s or more after contact with a simulated gastric fluid when the viscosity is measured with the following viscosity method: the viscosity is measured using a Brookfield rotational viscometer at a measurement Temperature of 20°C and a rotation rate of 6 rpm; wherein the viscosity before contact with gastric fluid is measured by placing 80 g of the concentrated liquid food in a cylindrical glass tube (inner diameter = 35 mm, height = 100 mm) that can be hermetically-sealed with a cap; and wherein the viscosity after contact with gastric fluid is measured by placing 16 g of simulated gastric fluid (an aqueous solution containing 0.7% hydrochloric acid and 0.2% common salt; pH = 1.2) in the cylindrical glass tube, adding 64 g of concentrated liquid food, sealing the cylindrical glass tube with a cap, and shaking the glass tube upside-down five times so as to mix the simulated gastric fluid with the concentrated liquid food; the mixture is left to stand at 38°C for 30 minutes; the temperature is then returned to 20°C, and the viscosity is measured. a polysaccharide which is one or more members selected from the group consisting of pectins, and alginic acids or salts thereof that becomes gelated or thickened by combining with calcium; 0.005 mass% to 0.25 mass% on a calcium basis of a water-soluble calcium source having a solubility of 0.1 g/100 mL or more at 20.0°C under a pH of 7.0; 0.10 mass% to 2.0 mass% of at least one member selected from the group consisting of trisodium citrate and tripotassium citrate; a protein having emulsifiability; and 0.2 mass% to 5.0 mass% of a soybean hemicellulose, the viscosity is measured using a Brookfield rotational viscometer at a measurement Temperature of 20°C and a rotation rate of 6 rpm; wherein the viscosity before contact with gastric fluid is measured by placing 80 g of the concentrated liquid food in a cylindrical glass tube (inner diameter = 35 mm, height = 100 mm) that can be hermetically-sealed with a cap; and wherein the viscosity after contact with gastric fluid is measured by placing 16 g of simulated gastric fluid (an aqueous solution containing 0.7% hydrochloric acid and 0.2% common salt; pH = 1.2) in the cylindrical glass tube, adding 64 g of concentrated liquid food, sealing the cylindrical glass tube with a cap, and shaking the glass tube upside-down five times so as to mix the simulated gastric fluid with the concentrated liquid food; the mixture is left to stand at 38°C for 30 minutes; the temperature is then returned to 20°C, and the viscosity is measured.