USDA nutritional guidelines underwent their first major revision in the midst of World War II. Published in 1943, the National Wartime Nutrition Guide introduced the Basic Seven food groups:
green and yellow vegetables
oranges, tomatoes, grapefruit
potatoes and other vegetables and fruits
milk and milk products
meat, poultry, fish, or eggs
bread, flour, and cereals
butter and fortified margarine.
A poster distributed to promote the Basic Seven encouraged Americans with this line: “For Health… eat some food from each group…every day!” Each of the seven groups paralleled important parts of nutrition grounded in scientific studies. Green and yellow vegetables, for instance, provide niacin, which prevents pellagra, while oranges, tomatoes, and grapefruit are among the best sources of vitamin C, which wards off scurvy. However, to accommodate wartime restrictions and scarcities, the USDA bulletin incorporated suggestions for substitutions. No oranges, tomatoes, and grapefruits? The guide suggested extra servings of different “green and yellow vegetables” and “potatoes and other vegetables and fruits.”
Following the war, the USDA updated the National Wartime Nutrition Guide and reissued it as the National Food Guide: Eat This Way Everyday. Prompted by the recent introduction of recommended daily allowances, the revised guide included information about the number of servings from each group that should be incorporated into the daily diet. These servings of so-called “foundation foods” were to be supplemented with additional items to round out meals.
With the Basic Seven, the USDA shared nutrition information visually. The kinds of information found in the thirty and seventy page Extension Service circulars common in the 1910s and 1920s were summarized and represented in a single image. This meant nutritionists had to simplify the vast knowledge about nutrition and highlight the most important parts.
By this time, the USDA had become a leader in nutrition research and advice and a source of national standards. The Home Demonstration division of the North Carolina Extension Service incorporated the USDA’s shifting dietary recommendations into its own printed materials and presentations. A similar rendition of the Basic Seven poster can be seen, for instance, in pictures of home demonstrations events in North Carolina, and the Extension Service’s Raise a Square Meal Around Home used the Basic Seven as a basis for planning foods grown and produced at home.