Your diet is composed of foods that contain carbohydrates, lipids, proteins and nucleic acids. These are the four types of macromolecules, or large molecules, needed for health. A well-balanced eating plan should include the recommended amount of each food component.
Foods that supply carbohydrates include grains, fruits and vegetables; protein is found in animal products and beans; and fats or lipids are provided by oils, fatty fish, nuts and red meat.
Food Sources of Carbohydrates
The three types of carbohydrates are starches, sugars and fiber, notes the American Diabetes Association. The Centers for Disease Control and Prevention (CDC) lists starchy foods as: beans, lentils, peas, grains and starch-containing vegetables such as corn, potatoes, parsnips, winter squash and yams. Sugar sources include the natural sugars in milk and fruit, along with white sugar, brown sugar, molasses, honey and corn syrup.
Plant foods are plentiful in fiber. High-fiber foods are fruits, vegetables, beans, peas, lentils and nuts like pecans and cashews, states the CDC. This category of carbohydrates also includes whole grains such as barley, oats and brown rice. In addition, it involves foods made with whole-grain flour like breads, pastas and cereals comprised of 100 percent whole-wheat or 100 percent whole grains.
Refined grains are also carbohydrates. Examples are white rice and pasta, bread and baked goods made with white flour, says the CDC. Muffins, crackers, cookies and cakes are refined grains. In contrast to whole grains, these foods are devoid of fiber and low in vitamins.
Instead of looking for either low- or high-carb foods when choosing carbohydrates, pick healthy carbs over unhealthy carbs. According to the CDC, good options involve those that are rich in vitamins, fiber and water but low in calories, fat and sugar.
Read more: List of Healthy Carbs
To illustrate what this would look like in the diet, eat brown rice instead of white rice, and replace potatoes and corn with nonstarchy vegetables like carrots and broccoli, suggests the CDC. Shun bread made with refined flour in favor of bread made with 100 percent whole-grain flour. Instead of indulging in a sugary dessert like apple pie, try a baked apple sprinkled with cinnamon and cloves.
The importance of carbohydrates for health is paramount because the right choices make a huge difference. Fruits, vegetables and whole grains are filled with beneficial nutrients for wellness, but refined grains increase the risk of Type 2 diabetes, states the Asian Diabetes Prevention Initiative.
Food Sources of Lipids
Like carbohydrates, food sources of lipids, or fats, are healthy or unhealthy. Healthy selections are monounsaturated and polyunsaturated fatty acids, which reduce cardiovascular risk, and unhealthy picks are saturated and trans fat, which are linked to elevated cholesterol, explains MedlinePlus. Foods with a high omega-3 fatty acid content are associated with decreased inflammation, but foods with a high omega-6 fatty acid content are linked to increased inflammation, notes the Arthritis Foundation.
Limit your consumption of saturated-fat foods, such as beef, and avoid eating trans fat, which is found in margarine and shortening. Healthy fat choices include fatty fish like salmon, olive oil, raw nuts, avocados, eggs and flaxseeds, states the Academy of Nutrition and Dietetics.
Food Sources of Protein
While people commonly associate protein with animal foods, such as meat, poultry, seafood, eggs and dairy products, many plant foods are also rich in protein, says the USDA. These include seeds, nuts, peas and beans, including soy products like tofu.
The USDA advocates getting protein from a variety of food sources. Because fatty fish like salmon and tuna are rich in healthful omega-3 fatty acids, feature them in a meal at least twice a week. Plant protein sources are appropriate for either a side dish or the main dish.
Examples include stir-fry tofu, bean soup or hummus, a spread made with chickpeas. Unsalted nuts make a nutritious snack, but you can also add them to salads or use them to replace meat in main dishes. The National Cancer Institute warns that red and processed meats are linked to cancer, so try to limit them in your diet.
Food Sources of Nucleic Acids
The Center on Disability Studies defines nucleic acids as the genetic material, or DNA, of an organism within the cells. When you eat food from animals, you're actually consuming the cells and all they contain, including the DNA.
Nucleotides are the building blocks that make up nucleic acids. Dietary sources of nucleotides include animal muscle from poultry, organ meats and seafood, as well as baker's yeast, says NovoCIB.
A January 1990 study published in Zeitschrift für Lebensmittel-Untersuchung und -Forschung found that certain vegetables contain nucleic acid components. These include leeks, cauliflower, broccoli, spinach, Chinese cabbage and certain varieties of mushrooms.
Read more: Foods High in Nucleic Acids
Putting the Nutrients Together
The Harvard T.H. Chan School of Public Health provides the following guidance on how to eat healthy, balanced meals:
- Fill half of your plate with fruits and vegetables. Vary the types you eat, so you'll ingest a range of colors. (Different-colored produce contain different nutrients.)
- Fill a fourth of your plate with whole grains. They're better for blood sugar control than refined grains.
- Fill the remaining fourth of your plate with protein foods. Nuts, beans, chicken and fish are healthy options.
- Include healthy plant oils, such as olive oil, in moderation.
- Instead of drinking sugary beverages, drink coffee, tea or water.
It's also helpful to understand how these guidelines translate into servings. The American Heart Association suggests these daily amounts:
- Fruits: Four servings
- Vegetables: Five servings
- Whole grains: Three to six servings
- Oils: 3 tablespoons
- Dairy: Three servings
- Proteins: One to two servings
The Academy of Nutrition and Dietetics has special dietary recommendations for women:
- Prior to menopause, consume extra iron. Excellent food sources include spinach, kale, beans and fish.
- Eat more folate foods in the childbearing years. Good sources are citrus foods, leafy vegetables and beans.
- For healthy bones and teeth, eat calcium-rich foods like yogurt and cheese.
Men have special dietary needs, too, says the Academy of Nutrition and Dietetics. Because men are larger and have more muscles than women, they need more calories — 2,000 to 2,800 per day for those who are moderately active. Though men are typically fond of meat, they can benefit from including more plant-based protein in their diet.
- Centers for Disease Control and Prevention: "More About Carbs"
- MedlinePlus: "Dietary Fats Explained"
- Arthritis Foundation: "Fats and Oils to Avoid"
- Academy of Nutrition and Dietetics: "Choose Healthy Fats"
- USDA Choose MyPlate: "All About the Protein Foods Group"
- Asian Diabetes Prevention Initiative: "Refined Grains"
- USDA Choose MyPlate: "Tips: Vary Your Protein Routine"
- National Cancer Institute: "Red Meat and Processed Meat Consumption"
- Center on Disability Studies: "Biomolecules in My Food"
- NovoCIB: "Nucleotide Metabolism Explorer"
- Zeitschrift für Lebensmittel-Untersuchung und -Forschung: "Nucleic Acid Components in Carbohydrate-Rich Food"
- Harvard T.H. Chan School of Public Health: "Healthy Eating Plate"
- American Heart Association: "What Is a Healthy Diet? Recommended Serving Infographic"
- Academy of Nutrition and Dietetics: "Healthy Eating for Women"
- Academy of Nutrition and Dietetics: "Healthy Eating for Men"
- American Diabetes Association: "Types of Carbohydrates"
- Texas Heart Institute; Nutrition; June 2011
- U.S. Department of Agriculture; Dietary Guidelines for Americans 2010; January 2010
- Center for Disease Control and Prevention; Food Groups; February 2011