The United States Department of Agriculture publishes the most familiar, healthy-eating visual guide, known as the "food pyramid" or "my pyramid." Based on the premise that eating a variety of foods provides all the nutrients necessary for the body's requirements, the food pyramid design uses colored triangles to represent the six food groups. These triangles vary in width, depending upon the number of daily servings recommended by the USDA. Although other food pyramids, such as Harvard's School of Public Health's "Healthy Eating Pyramid" exist, the USDA's pyramid remains the most widely used and recognized.
Grains, the Orange Triangle
The widest of the triangles, the grain group contains whole and processed grains. The USDA affirms that whole grains provide higher nutrient densities than processed grains. Recommended daily servings depend on age and gender with lower amounts at a 3-ounce limit to higher amounts of an 8-ounce limit, according to the My Pyramid website.
Vegetables, the Green Triangle
The vegetable group contains five subgroups. One subgroup, the starchy vegetables convert, in part, to sugar once metabolized by the body. The USDA recommends that you consume more dark greens for the calcium content, orange vegetables for their beta-carotene and dry beans and peas for the high-fiber content, rather than relying too heavily on the starchy vegetables. One hundred percent vegetable juice also counts as a serving of vegetables. Adults should consume at least three servings of vegetables daily.
Fruits, the Red Triangle
The fiber provided by the fruit group helps keep blood cholesterol levels in check, which also reduces the risk of developing heart disease, according to the USDA. Fruits contain high amounts of potassium, vitamin C and folic acid as well. Given their easy portability, fresh fruits make nutritious in-between meal snacks, the pyramid suggests. One to 2 cups per day of fruit fills your daily needs.
Oils, the Yellow Triangle
Oil, the smallest of all the food pyramid triangles, contains essential fatty acids vital to cellular functioning. The monounsaturated and polyunsaturated fats in foods such as fish, nuts and some vegetables, support the health of your organs. The USDA counts 1 teaspoon of oil as a serving, and adults need between 5 and 7 teaspoons per day.
Milk, the Blue Triangle
The milk group contains a wide variety of food choices. These multiple choices keeps you from relying solely on milk to get your recommended daily servings. Cheese, yogurt, pudding and lactose-free products all fall under the milk group. Choose 3 cups of low-fat or fat-free selections daily to receive your recommended levels of calcium.
Meat & Beans, the Purple Triangle
The last food group contains your daily protein needs. The USDA recommends eating fish, beans, seeds and nuts in addition to lean cuts of meats and poultry. Black-eyed peas and chickpeas also fall under the meat and beans group. Adults need between 5 and 6 ounces daily.