10.8: Nutrition
If obesity rates are high in the U.S., we might safely assume that nutritional status is poor on average as well. Since 1980, the USDA has published nutritional guidance in the Dietary Guidelines for Americans with updates every 5 years to align recommendations with current nutrition science (USDA and HHS, 2020). The purpose of these guidelines is to promote health and prevent disease in the U.S. population, not to prescribe specific diets for each individual. In the 1990s, the USDA adopted the “Food Pyramid” to provide a visualization of daily servings for different food groups. In 2011 this was revised to Choose My Plate which created a much easier visual representation of the guidelines in the form of a plate (Raikar, 2023). The most recent guidelines also place emphasis on ethnic and cultural variations in dietary patterns and how the guidelines can be applied in enjoyable and affordable ways (USDA and HHS, 2020). Below are the overarching guidelines in the most recent iteration (2020-2025):
- Follow a healthy dietary pattern at every life stage.
- Customize and enjoy nutrient-dense food and beverage choices to reflect personal preferences, cultural traditions, and budgetary considerations.
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Focus on meeting food group needs with nutrient-dense foods and beverages, and stay within calorie limits. Food groups include:
- Vegetables of all types - dark green; red and orange; beans, peas, and lentils; starchy; and other vegetables
- Fruits - especially whole fruits
- 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.
- Limit foods and beverages higher in added sugars, saturated fat, and sodium, and limit alcoholic beverages (USDA and HHS, 2020).
The ChooseMyPlate model visually represents relative portion sizes for each major food group. See Figure 10.4 below.
Researchers and epidemiologists utilize a scoring system to compare current eating habits of Americans with the dietary guidelines. This score is called the Health Eating Index (HEI) and is reflective of diet quality not quantity (or number of calories consumed). Between 2005-2006 and 2015-2016, HEI scores taken from NHANES data have averaged around 56-60/100. This reflects a persistence in typical eating patterns remaining far below the dietary guidelines in terms of quality (USDA and HHS, 2020). In terms of quantity, we are certainly eating more. United Nations publications indicate that total calorie consumption is up worldwide in the past two decades, increasing by 9% between 2021 and 2022 to an average of 2960 kcals per day. In Europe and North America, the average was 3,540 kcal per day (United Nations News, 2022). Data from the USDA suggest that average daily consumption per capita in the 1970’s was just over 2,000 kcal. Although dietary fads come and go, Americans are certainly consuming more grains, fats than we used to (DeSilver, 2016), and the consumption of sugar-sweetened beverages is up in the U.S. and worldwide (Lara-Castor et al., 2023).