The present invention relates to a liquid nutritional composition, to a liquid nutritional composition for use in a diagnostic method for screening of a glucose-intolerant condition, to a kit for screening of a glucose-intolerant condition, and to a diagnostic method for screening a mammal for a glucose-intolerant condition. Furthermore, it refers to a liquid nutritional composition for use as a standard reference nutrition, such as for classification of postprandial glucose responses of different nutritional compositions. The liquid nutritional composition comprises protein, fat, digestible carbohydrate and dietary fibre, wherein the digestible carbohydrate comprises at least 90 weight % of glucose units, based on total digestible carbohydrate mass and preferably is substantially free of fructose.