It seems that someone in the government just can’t decide how many food groups there should be. It all started back in 1916 with five food groups. By 1933, the groups had ballooned to twelve. In the early 40s due to wartime food shortages, the groups were scaled back to a more manageable seven, which included Butter and Margarine as its own group.

The 1943 Food Wheel

The Basic 7 Food Guide was established in 1943 and continued to be used until 1955

Not to make anyone feel too restricted to these seven groups, the USDA added “eat any other foods you want” to their guide.

In the 50s, we were down to four groups: milk, meat, fruits and grains.

The Basic 4

In 1979, Sugar, Fat and Alcohol group appeared.

1979's "Hassle-Free Food Guide"

The Food Pyramid was introduced in 1992 to be replaced by The Plate in 2011.

Source: PCRM.com