The first US dietary recommendations were set by the National Academy of Sciences in 1941. The recommended dietary allowances (RDA) were first established out of concern that America’s overseas World War II troops were not consuming enough daily nutrients to maintain good health. The first Food and Nutrition Board was created in 1941, and in the same year set recommendations for the adequate intakes of caloric energy and eight essential nutrients. These were disseminated to officials responsible for food relief for armed forces and civilians supporting the war effort. Since 1980, the dietary guidelines have been reevaluated and updated every five years by advisory committees of the US Department of Agriculture (USDA) and the US Department of Health and Human Services (HHS). Each new set of guidelines evolves from a systematic review of peer-reviewed nutrition research, analysis of American eating habits, and assessment of how changes in food patterns may affect health. These reviews are carried out by an advisory committee of experienced nutrition professionals. Public comment is invited at all stages of the development process. ^[1]

Before 1980, dietary recommendations focused only on preventing nutrient inadequacy. More recently, an understanding of the importance of nutrition in preventing chronic disease has led to a broader focus on promoting health. The seventh edition of the Dietary Guidelines was released in 2010 and focused mainly on combating obesity. The 2015 Dietary Guidelines focused on eating patterns predictive of overall health status and disease risk, rather than focusing on individual foods or nutrients. The 2020 Dietary Guidelines continue the focus on healthy dietary patterns and add consideration of how dietary needs change across the lifespan. The 2020 Dietary Guidelines are the first to provide specific recommendations for all life stages, including pregnancy and lactation.

Establishing Human Nutrient Requirements for Worldwide Application

The United Nations (UN) and the World Health Organization (WHO) work together to establish human nutrient requirements that apply worldwide. The WHO’s Department of Nutrition for Health and Development, in collaboration with the Food and Agriculture Organization of the United Nations (FAO), continually reviews new research and information from around the world on human nutrient requirements and recommended nutrient intakes. This is a vast and never-ending task, given the large number of essential human nutrients. These nutrients include protein, energy, carbohydrates, fats and lipids, a range of vitamins, and a host of minerals and trace elements.

Many countries rely on WHO and FAO to establish and disseminate this information, which they adopt as part of their national dietary allowances. Others use it as a base for their standards. The establishment of human nutrient requirements is the common foundation for all countries to develop food-based dietary guidelines for their populations.

Establishing requirements means that the public health and clinical significance of intake levels – both deficiency and excess – and associated disease patterns for each nutrient, need to be thoroughly reviewed for all age groups. Every ten to fifteen years, enough research is completed and new evidence accumulated to warrant WHO and FAO undertaking a revision of at least the major nutrient requirements and recommended intakes.^[2]

Why Are Guidelines Needed?

Instituting nation-wide standard policies provides consistency across organizations and allows health-care workers, nutrition educators, school boards, and eldercare facilities to improve nutrition and subsequently the health of their respective populations. The Dietary Guidelines are used to set nutrition policy, support nutrition education, and guide disease prevention efforts at local, state, and national levels.^[3]

At the same time, the Dietary Guidelines provide information that will help any interested person in obtaining optimal nutritional balance and health. The healthy eating patterns identified are designed to be adaptable to individual preferences, budgets, and cultural foodways.

Major Themes of the 2020 Dietary Guidelines^[4]

The four key, overarching guidelines for 2020 are:

1. Follow a healthy dietary pattern at every life stage.
2. Customize and enjoy nutrient-dense food and beverage choices to reflect personal preferences, cultural traditions, and budgetary considerations.
3. Focus on meeting food group needs with nutrient-dense foods and beverages, and stay within calorie limits.
4. Limit foods and beverages higher in added sugars, saturated fat, and sodium, and limit alcoholic beverages.

Let’s look at each of these in a little more detail:

Guideline 1: Follow a healthy dietary pattern at every life stage.

It’s recommended to feed infants human milk for the first 6 months of life, or iron-fortified formula if human milk is not an option.  Supplemental vitamin D is also recommended at this stage. At about 6 months, you can begin introducing infants to nutrient-dense foods, encouraging variety and foods rich in iron and zinc.  From 12 months through adulthood, the focus is on healthy dietary patterns. A dietary pattern is the combination of foods and beverages an individual consumes over time. Focusing on dietary patterns instead of individual foods acknowledges that health is affected more by our overall diets as a whole than by single foods or nutrients.

There are many different ways to achieve a healthy dietary pattern, but there are some key principles that help no matter what your preferences or traditions:

• Meet nutritional needs primarily from foods and beverages.
• Choose a variety of options from each food group.
• Pay attention to portion size.

Dietary patterns associated with greater health include more nutrient-dense foods such as vegetables, fruits, legumes, whole grains, lean protein, and healthy oils. Dietary patterns associated with poorer health outcomes include more red meat, processed meats, sugary foods and beverages, and refined grains.  Healthy dietary patterns also provide the amount of calories an individual needs at all stages of life, whether they are older or younger, less or more physically active, and whether they need to gain, lose, or maintain weight.

Guideline 2: Customize and enjoy nutrient-dense food and beverage choices to reflect personal preferences, cultural traditions, and budgetary considerations.

As mentioned above, there are many different ways to achieve a healthy dietary pattern. Each food group contains a variety of nutrient-dense options, allowing the individual to choose what they prefer. There are also nutrient-dense options within every cultural tradition. Budget constraints can make acquiring healthy foods more challenging for a variety of reasons, but even on a budget more nutrient-dense choices can be made. Canned, dried, and frozen food can be used in place of fresh food to extend storage options and reduce food waste.

Guideline 3: Focus on meeting food group needs with nutrient-dense foods and beverages, and stay within calorie limits.

Nutrient-dense foods provide essential vitamins and minerals without a lot of added sugars, unhealthy fats, or sodium. Selecting nutrient-dense foods and beverages help you meet your nutritional needs without consuming more calories than you need.

The core elements that make up a healthy dietary pattern include:

• Vegetables of all types—dark green; red and orange; beans, peas, and lentils; starchy; and other vegetables
• Fruits, especially whole fruit
• Grains, at least half of which are whole grain
• Dairy, including fat-free or low-fat milk, yogurt, and cheese, and/or lactose-free versions and fortified soy beverages and yogurt as alternatives
• Protein foods, including lean meats, poultry, and eggs; seafood; beans, peas, and lentils; and nuts, seeds, and soy products
• Oils, including vegetable oils and oils in food, such as seafood and nuts

Most Americans do not get enough vegetables, fruits, or dairy in their diet. To increase intake of these food groups, look for nutrient-dense options, such as vegetables without added butter or sodium, fruits without added sugar, and low- or non-fat dairy or dairy alternatives.  Most of your fruit intake should come from whole fruit, not juice. Most Americans do get enough total grain in their diet, but could improve their intake of whole grains. Protein intake can come from both animal and vegetarian sources. Most Americans could increase their intake of seafood and beans, peas, and lentils to improve variety of their protein sources.  Reducing intake of processed meats (e.g. salami, sausages, hot dogs) or high-fat meat can help reduce your intake of sodium and unhealthy fats.

Guideline 4: Limit foods and beverages higher in added sugars, saturated fat, and sodium, and limit alcoholic beverages.

The 2020 Dietary Guidelines recommend the following limits:

• Added sugars: Less than 10 percent of calories per day starting at age 2. Avoid foods and beverages with added sugars for those younger than age 2.
• Saturated fat: Less than 10 percent of calories per day starting at age 2.
• Sodium: Less than 2,300 milligrams per day—and even less for children younger than age 14.
• Alcoholic beverages: 2 drinks or less per day for men and 1 drink or less per day for women is considered a moderate intake of alcohol. Alcohol is not required for a healthy diet and should not be consumed by people who are pregnant.

Intake of trans fats and dietary cholesterol is recommended to be as low as possible.