Provided is a method for producing an oil-in-water emulsified food product composition. The method includes adding an oil and fat containing a highly hydrophilic emulsifier or a mixture of an oil and fat containing a highly hydrophilic emulsifier and water to water or an aqueous solution of water-soluble minerals and mixing them, then adding a protein or a protein and an additional component, and heating and sterilizing the composition, and the oil and fat contains a medium chain fatty acid in a ratio of more than 0.1% by weight and less than 100% by weight with respect to the total fatty acid composition. The method can suppress foaming of the oil-in-water emulsified food product composition during mixing, can also generate no phase separation or aggregates or extremely suppress the generation after heat sterilization, and can further maintain the stability of components susceptible to oxidation, such as vitamins during preservation if such a component is contained, thus producing a high quality oil-in-water emulsified food product composition.