Following an application from Nestlé S.A. submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 the Competent Authority of Belgium, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to beta-glucans from oats and/or barley in a ready-to-eat cereal manufactured pressure cooking and reduction of blood glucose rise after consumption. The scope of the application was proposed to fall under a health claim based on newly developed scientific evidence. The food proposed is 'beta-glucans from oats and/or barley incorporated into ready-to-eat breakfast cereals manufactured pressure cooking'. The applicant proposed that at least 1.3 g of beta-glucans/25 g of available carbohydrates in ready-to-eat breakfast cereals manufactured pressure cooking should be consumed. Beta-glucans from oats, barley or any combination thereof incorporated into ready-to-eat cereals manufactured by pressure cooking, are sufficiently characterised. The claimed effect proposed is 'reduction of the blood glucose rise after the meal'. The reduction of post-prandial glycaemic responses (as long as post-prandial insulinaemic responses are not disproportionally increased) may be a beneficial physiological effect. One human intervention study showed an effect of beta-glucans from oats and/or barley, incorporated into breakfast cereals manufactured pressure cooking at a level of at least 1.2 g/25 g available carbohydrates, on decreasing post-prandial glycaemic responses without disproportionally increasing insulinaemic responses. Dose-response relationships were not tested, and no evidence has been provided that beta-glucans incorporated into cereals processed using pressure cooking would exert a higher effect on post-prandial glucose responses than beta-glucans added to other carbohydrate containing foods. Whereas the effect of beta-glucans in reducing post-prandial blood glucose responses is well established, the evidence provided is insufficient to establish such an effect at doses of 1.3 g beta-glucans per 25 g of available carbohydrate incorporated into ready-to-eat breakfast cereals manufactured via pressure cooking (i.e. either batch cooking or extrusion).