Oatmeal is also used as a thickening agent in savory Arabic or Egyptian meat-and-vegetable soups, and sometimes as a way of adding relatively low-cost fibre and nutritional content to meatloaf.

Unenriched oatmeal, cooked by boiling or microwaving, is 84% water and contains 12% carbohydrates, including 2% dietary fiber, and 2% each of protein and fat (table).

[9] In Ireland, stirabout (Irish: leite)[10] was formerly a staple food, made by stirring oatmeal into boiling water or milk to form a thin soup.

[11][12] Because of its cheapness, and the ease with which it could be prepared in large quantities, stirabout was widely served in institutions like prisons, boarding schools, convents, and workhouses.

[16][17][18] Oatmeal has a long history in Scottish culinary tradition because oats are better suited than wheat to the country's low temperatures and high humidity.

The ancient universities of Scotland had a holiday called Meal Monday to permit students to return to their farms and collect more oats for food.

Samuel Johnson referred, disparagingly, to this in his dictionary definition for oats: "A grain, which in England is generally given to horses, but in Scotland supports the people."

Throughout the Netherlands, the Nordic countries, the Baltic states and Russia, oatmeal porridge made from rolled oats and water or milk is a traditional breakfast staple.

Local names for the porridge include Dutch havermoutpap, Swedish havregrynsgröt, Danish havregrød, Norwegian havregrøt or havregraut, Icelandic hafragrautur, Finnish kaurapuuro, Estonian kaerahelbepuder, Latvian auzu pārslu (putra), Lithuanian avižinių dribsnių košė, Polish owsianka and Russian овсянка (ovsyanka).

[27] In the United States, oatmeal is often served as a porridge[28] with milk or cream and a sweetener, such as brown sugar, honey, or maple syrup.