We found possibilities for fermented bilberries, European wild-growing low-bush blueberries (Vaccinium myrtillus), in the formulation of foods with metabolic merits.Fermented bilberries were seen to reduce insulin demand after a high-sugar containing drink in humans.A major challenge of nutrition science is the combat of diet related disorders, in particular, diseases connected to the insulin resistance syndrome.Quality parameters of importance in this connection are the postprandial glucose and insulin responses, where foods characterized by a low glycaemic index (GI) or glycaemic load (GL) have been found to induce benefits on several risk markers for this syndrome as judged from interventions in healthy and type 2 diabetic subjects.We have measured glycemic and insulinemic responses in young healthy adults in four studies after intake of high-sugar drinks without and with raw or processed bilberries.Our results show a dose-response relationship, so that an increased addition of raw homogenized bilberries decreased the postprandial insulin responses and to some extent also blood glucose responses.The active components could not be detected to either the peel or juice, but is present in both fractions.However, pasteurization and fermentation with lactic acid bacteria showed the most important effect, reducing the insulin response by 25% after intake as a high-sugar bilberry drink.Consequently a drink added with fermented bilberries induced a lower insulin response than expected from the glycemic response.The determined GI values were high and in good agreement with those calculated according to the content of digestible carbohydrates and their GI values.However, the high glucose response was not accompanied by an expected high insulin response.The insulin demand, if expressed as a relationship between insulinemia and glycemia (II/GI) was low or 0,6.In summary, a fermented high-sugar bilberry drink induced a lower insulin response than expected from the glycaemic response.The mechanism for the lower acute insulin demand is still unclear, but seems to be related to the fermentation process.