Every five years, the United States Department of Agriculture (USDA) and Health and Human Services (HHS) jointly update and publish a set of guidelines designed to help Americans improve their health by making wise dietary decisions. The most recent guidelines were just released today.
The new Dietary Guidelines for Americans, 2010, focuses on balancing calories (fewer calories taken in and more burned with physical activity), and encourages Americans to consume more healthy foods like vegetables, fruits, whole grains, fat-free and low-fat dairy products, a variety of seafood, and to consume less sodium, saturated and trans-fats, added sugars, and refined grains. I've got the highlights of the new guideline and a few tips, ready to go:
Highlights of the Dietary Guidelines for Americans, 2010
You can also read the entire guideline at the USDA's DietaryGuidelines.gov.
I think these should come out every three years or less to keep up with research.