The U.S. Department of Agriculture has been issuing dietary recommendations for over 100 years. As the research base underlying these recommendations has expanded considerably over the century, dietary recommendations have evolved to keep pace with both the new findings and the changing patterns in food consumption and activity of the population. In spite of these changes, many of today ís dietary recommendations remain impressively similar to those of yesterday.
from chapter two in: America’s Eating Habits: Changes and Consequences by Elizabeth Frazao
Agriculture Information Bulletin No. (AIB-750) 494 pp, May 1999