Objective: To evaluate the impact of an extruded muesli product based on beta-glucan-rich oat bran on postprandial glycaemia and insulinaemia.
Subject/design: The study is divided in two series. Blood glucose and serum insulin responses were studied after subjects consuming test meals including a serving of muesli with 3 g (series 1) and 4 g (series 2) of beta-glucans, respectively. The muesli was a component in a single serving packet with muesli and yoghurt. This was served together with white wheat bread in the morning after an overnight fast. The compositions were standardized to contain 50 g available carbohydrates. As a reference meal a serving packet without beta-glucans was included. The study was performed at Applied Nutrition and Food Chemistry, Lund University, Sweden. Nineteen and thirteen healthy volunteers with normal body mass index were recruited for series 1 and 2, respectively.
Results: Muesli with 3 g of beta-glucans, included in a mixed bread meal, gave no significant differences in glycaemic response compared to a reference meal without muesli and beta-glucans. In contrast, muesli with 4 g of beta-glucans significantly (P<0.05) lowered the glucose and insulin responses compared to the reference meal.
Conclusions: Muesli enriched with 4 g of beta-glucans reduces postprandial glucose and insulin levels to a breakfast based on high glycaemic index products. A total of 4 g of beta-glucans from oats seems to be a critical level for a significant decrease in glucose and insulin responses in healthy people.