Chapter 2 – Planning Healthy Diets
2.5 Tools for Achieving a Healthy Diet
Many nutrients from food literally become part of your body, while others help regulate metabolism, immunity, and energy production.
The phrase “you are what you eat” also highlights the cumulative effects of food choices over time. Many nutrients obtained from food quite literally become part of the body. For example, the protein and calcium found in milk can be used to build and maintain bone tissue. Other nutrients influence metabolism, immune function, and energy levels, shaping how we feel on a daily basis and our long-term health.
The foods we choose affect not only how we feel today, but also our risk for chronic diseases such as heart disease and type 2 diabetes, our ability to maintain a healthy body weight, and our overall quality of life. In the sections that follow, we will explore the key components of a healthy dietary pattern and how thoughtful food choices support health across the lifespan.
Components of a Healthy Diet
Achieving a healthy diet is a matter of balancing the quality and quantity of food that you eat to provide an appropriate combination of energy and nutrients. The four key characteristics that make up a healthful diet are discussed below and include 1) adequacy, 2) balance, 3) moderation, and 4) variety. [1]
1. Adequacy
A diet is adequate when it provides sufficient amounts of calories and each essential nutrient, as well as fiber. Most Americans do not eat enough fruits, vegetables, whole grains, or dairy, which increases the risk of inadequate intake of fiber, calcium, potassium, and other essential nutrients.
2. Balance
A balanced diet includes foods from all the major food groups. No single food provides everything your body needs, so eating foods from all the food groups helps ensure adequate nutrition.
3. Moderation
Moderation means avoiding extremes by enjoying all foods in appropriate portions. Small amounts of foods higher in added sugars or solid fats can fit into a healthy diet, making healthy eating more enjoyable and sustainable.
4. Variety
Variety refers to consuming different foods within each food group regularly. Eating a varied diet helps to ensure that you consume adequate amounts of all essential nutrients required for health. One major drawback of a monotonous diet is the risk of consuming excessive amounts of certain nutrients and insufficient amounts of others. Trying new foods can also be a source of pleasure—you never know what foods you might like until you try them.
Dietary Guidelines for Americans
The Dietary Guidelines for Americans are developed jointly by the U.S. Department of Agriculture (USDA) and the U.S. Department of Health and Human Services (HHS) and updated every five years. The current edition, the Dietary Guidelines for Americans, 2025–2030, emphasizes healthy eating patterns across the lifespan, food quality, protein adequacy, and limiting ultra-processed foods. Rather than focusing on individual nutrients, the Guidelines emphasize overall dietary patterns that support health and reduce the risk of chronic disease. The seven key messages are summarized below. [2]
Key Messages from the Dietary Guidelines for Americans, 2025–2030
1. Eat the Right Amount for You
Calorie needs vary by age, sex, height, weight, and physical activity level. Eating an appropriate amount supports energy balance, metabolic health, and long-term well-being.
2. Prioritize Protein Foods at Every Meal
Protein supports growth, tissue maintenance, immune function, and metabolic health. Include high-quality, nutrient-dense protein foods at each meal.
3. Consume Dairy
Dairy goal: 3 servings per day in a 2,000-calorie dietary pattern, adjusted as needed.
4. Eat Vegetables and Fruits Throughout the Day
Vegetables and fruits provide essential vitamins, minerals, fiber, and bioactive compounds. Eat a variety of colorful vegetables and fruits daily.
5. Incorporate Healthy Fats
Healthy fats support nutrient absorption and overall health and are naturally found in many whole foods such as seafood, nuts, seeds, olives, and avocados.
6. Focus on Whole Grains
Whole grains provide fiber and essential nutrients and are preferred over refined grain products. Prioritize fiber-rich whole grains.
7. Limit Highly Processed Foods, Added Sugars, and Refined Carbohydrates
Highly processed foods are often high in added sugars, sodium, refined carbohydrates, and additives while offering limited nutritional value.
The full Dietary Guidelines for Americans, 2025–2030 report and supporting materials are available at realfood.gov.
Understanding the NOVA Classification System
Foods can be classified in many ways, including by the degree of processing they undergo. One commonly used system is the NOVA classification, developed by researchers in Brazil. NOVA groups foods into four categories based on the extent and purpose of processing.[3]
| NOVA Group | Description | Examples |
|---|---|---|
| Group 1: Unprocessed or Minimally Processed Foods | Foods are altered very little from their natural state | Apples, milk, eggs, oats |
| Group 2: Processed Culinary Ingredients | Ingredients used in cooking | Oil, butter, sugar, salt |
| Group 3: Processed Foods | Foods made by adding Group 2 ingredients to Group 1 foods | Cheese, canned beans, fresh bread |
| Group 4: Ultra-Processed Foods | Industrial formulations containing ingredients not commonly used in home kitchens | Soft drinks, packaged snack cakes, and many fast foods |
Researchers often use the NOVA system when studying dietary patterns and health outcomes. Many studies have found that diets high in ultra-processed foods are associated with poorer health outcomes. However, some experts argue that the NOVA system may oversimplify foods because processing itself does not always reduce nutritional quality. As a result, both the nutrient content of a food and its level of processing should be considered when making food choices.
USDA Food Guides
The U.S. government, like many countries, uses food guides to help people make healthy food choices. These guides have changed over time as nutrition science and public health priorities have evolved.
The Food Guide Pyramid (1992)
The Food Guide Pyramid was introduced in 1992 as a visual guide to healthy eating (Figure 2.18). It organized foods into groups and emphasized eating more foods from the base of the pyramid and fewer from the top. Although widely recognized, it was criticized for being overly simplistic and providing limited guidance on food quality, physical activity, and individual calorie needs.
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MyPlate Replaces MyPyramid (2011)
Because many consumers found MyPyramid confusing, the USDA introduced MyPlate in 2011 (Figure 2.20). The simple plate graphic was designed to help people visualize the types and proportions of foods recommended at each meal.
The New Pyramid (2026)
In 2026, MyPlate was replaced by the New Pyramid as part of the 2025–2030 Dietary Guidelines for Americans (Figure 2.21). The revised graphic emphasizes protein-rich foods, nutrient density, and the limitation of ultra-processed foods.
The New Pyramid generated considerable debate among nutrition and public health experts. Supporters argue that it places greater emphasis on food quality and reducing reliance on ultra-processed foods. Critics contend that it places too much emphasis on animal-based foods and may conflict with longstanding evidence supporting dietary patterns rich in fruits, vegetables, whole grains, and other plant foods.
This debate highlights an important point: dietary recommendations evolve over time as new research emerges and as experts weigh competing health priorities. As a result, food guides reflect not only nutrition science but also public health goals and differing interpretations of the available evidence.
Nutrient Density Versus Empty Calories
Nutrient density refers to the amount of beneficial nutrients a food provides relative to its calorie content. Nutrient-dense foods are rich in vitamins, minerals, fiber, and protein while being relatively low in added sugars, solid fats, and excess sodium. For example, a 3-ounce, 90% lean ground beef patty provides protein, iron, and other essential nutrients while offering fewer calories than a 75% lean patty. The additional calories in the 75% lean patty come primarily from 52 kcal of solid fat rather than nutrients.
Figure 2.22. Examples of the calories found in nutrient-dense food choices compared with the calories found in less nutrient-dense forms of these foods. (Image from The Dietary Guidelines for Americans 2010, Public Domain.)
DEFINING EMPTY-CALORIE FOODS
In contrast, foods high in empty calories contain large amounts of added sugars and solid fats while providing relatively few essential nutrients. For example, a fresh apple is a nutrient-dense food, but when it is made into a deep-fried apple pie with added sugar and a buttery crust, it contains many more empty calories and is much less nutrient-dense.
| Nutrient-Dense Foods | Foods Higher in Empty Calories |
|---|---|
| Apples and bananas | Apple pie and banana nut bread |
| Whole-grain bread or rolls | Cookies and donuts |
| Beans, nuts, and seeds | Candy and pastries |
| Lean meats and poultry | Fried chicken, bologna, or weiners |
| Plain milk and yogurt | Ice cream and puddings |
Keep in mind that small amounts of empty calories can fit into a healthy diet. For example, a teaspoon of sugar in oatmeal or a small amount of butter on vegetables may improve flavor and encourage consumption of nutrient-dense foods. The key is that these additions complement nutrient-rich foods rather than replace them.
Class Discussion Questions
- Think about what you ate yesterday. Which food groups were well represented, and which were missing or underrepresented? Based on the concepts of balance and variety, what changes could you make to improve your diet?
- Imagine you are choosing between a piece of fruit and a candy bar for a snack. Both provide calories, but one is considered more nutrient-dense. What makes a food nutrient-dense, and why might nutrient density be useful when making food choices?
- Many dietary recommendations encourage eating more fruits, vegetables, whole grains, and minimally processed foods. What challenges might college students face when trying to follow these recommendations? What practical strategies could help overcome those challenges?
- Do you agree with the statement, “There are no bad foods, only bad diets”? Why or why not? How does the concept of moderation influence your answer?
Review Questions
attributions
This section is an adaptation of “Tools for Achieving a Healthy Diet” in Nutrition: Science and Everyday Application by Alice Callahan, PhD; Heather Leonard, MEd, RDN; and Tamberly Powell, MS, RDN under a Creative Commons Attribution-NonCommercial 4.0 International License.
- Lawrence M. Fundamentals of a healthy and sustainable diet. Nutr J. 2024;23(1):150. Published 2024 Nov 30. doi:10.1186/s12937-024-01049-6 ↵
- U.S. Department of Agriculture, Food and Nutrition Service. Dietary Guidelines for Americans, 2025–2030. Accessed January 30, 2026. https://www.fns.usda.gov/cnpp/dietary-guidelines-americans ↵
- Rossi K, Gombi Vaca MF, Schwartz MB, Caspi C. Nutritional quality of foods according to the Nova food classification system after a behavioral economics intervention in food pantries. Front Public Health. 2025;13:1613200. Published 2025 Aug 29. doi:10.3389/fpubh.2025.1613200 ↵
A food classification system that groups foods into four categories according to the degree and purpose of processing, from minimally processed foods to ultra-processed foods.
Containing a high amount of vitamins, minerals, and protein compared to calories
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