Food group

[1] Food groups were a public health education concept invented to teach people eating very restricted, unvaried diets how to avoid becoming deficient in specific nutrients.

[2] Opson and sitos were Classical Greek food groups, mainly used for moral education, to teach sophrosyne.

Indian foodways had a substantial influence on European organisations such as the Vegetarian Society], which cited Indian diets as proof that a healthy vegetarian diet was possible, and were actively involved in public debate on nutrition.

In the 20th century, food groups became widely used in public health education, as a tool to reduce nutritional deficiencies.

As early as the 1980s, researchers were criticizing food groups, saying that they were a concept useful for teaching people to avoid nutritional deficiencies, but that nutritional deficiencies were no longer major cause of diet-related disease in affluent societies.

Grains, the largest groups food group in many nutrition guides, includes oats, barley and bread. Cookies, however, are categorized as sugar.
Vegetables, the second largest food group in many nutrition guides, come in a wide variety of shapes, colors and sizes.