Dry milling methods for preparing oat products enriched in the content of β-glucan and methods for preparing foodstuffs incorporating such an enriched oat product especially ready-to-eat cereals are provided. Heat conditioned dehulled oats are dry milled to form a coarse whole non defatted oat flour and then, without a preceding removal of fat, dry fractionated into coarser bran and finer oat flour fractions at multiple stages. The coarse oat flour is first dry classified to separate or form a coarser fraction oat bran containing more concentrated β-glucan and a finer oat flour or starch containing or endosperm containing fraction. The oat bran is subjected to second and third rounds of milling and classification to form a high β-glucan content (>7-9%) oat bran and a low β-glucan content (3%) oat flour. The oat bran and oat flours can be used to prepare foodstuffs such as ready-to-eat cereals.