Dietary Guidelines for Americans - 2015-2020 edition

+  These are the over-all guidelines: 

• Follow a healthy eating pattern across the lifespan. Eating patterns are the combination of foods and drinks that a person eats over time.
• Focus on variety, nutrient-dense foods, and amount
• Limit calories from added sugars and saturated fats, and reduce sodium intake
• Shift to healthier food and beverage choices
• Support healthy eating patterns for all

This is just an outline of what is included.  The committee writing the guidelines also publishes detailed information on each one.   Here are a few tips from them on what to eat if you wish to follow the guidelines:  

• A variety of vegetables, including dark green, red and orange, legumes (beans and peas), starchy and other vegetables
• Fruits, especially whole fruits
• Grains, at least half of which are whole grains
• Fat-free or low-fat dairy, including milk, yogurt, cheese, and/or fortified soy beverages
• A variety of protein foods, including seafood, lean meats and poultry, eggs, legumes (beans and peas), soy products, and nuts and seeds
• Oils, including those from plants: canola, corn, olive, peanut, safflower, soybean, and sunflower. Oils also are naturally present in nuts, seeds, seafood, olives, and avocados.

The office of the Secretary of Agriculture selects committee members who are known for their expertise in nutrition.  The guidelines are up-dated approximately every 5 years; and plans are already underway for selecting the next committee. 

Reliable sources for more details include;
dietaryguidelines.gov
choosemyplate.gov
eatright.org
The USDA
your local dietitian