Effects of Food Groups in Nutrition

The United States Department of Agriculture's food guide groups foods with similar nutritional value into six basic categories. Since no single food or drink provides every nutrient your body requires, regularly eating foods from these groups, in the right proportions, promotes good health through a balanced diet.

Grains

• The grain group of foods includes grains, pasta, bread, rice and cereals. At least half the grains you eat should be in the form of whole grains, according to the USDA. Complex carbohydrates in grains provide energy. Fiber-rich, whole-grain foods, such as brown rice, bulgar and oatmeal, are the best choice for proper functioning of the digestive system. Refined grains, with the bran and germ removed, contain less dietary fiber and iron and fewer B vitamins.

Vegetables

• The vegetable group of foods includes vegetable juice; dark green vegetables, such as romaine lettuce and spinach; starchy vegetables, such as corn and potatoes; orange vegetables such as squash and carrots; dry beans and peas, such as kidney and soybeans; and other vegetables, such as beets, tomatoes, cucumber and cauliflower. Vitamins A, E and C, and folate and fiber in vegetables may reduce the risk of certain cancers, including stomach, colon and mouth cancer, and protect against coronary heart disease. Potassium in vegetables may reduce the risk of kidney stones and bone loss, according to the USDA.

Fruit

• The fruit group includes fruit and juices, such as apples, berries, melons, bananas and citrus fruits. Fruits, naturally low in calories and fat, and sodium-free, are a good source of potassium, which helps maintain a healthy blood pressure level. They also contain vitamin C, important for cell repair and growth; and folate, which is necessary for the formation of red blood cells and to reduce the risk of neural tube defects during fetal development. Dietary fiber in fruit helps reduce cholesterol and promotes proper bowel function. Fruits may reduce the risk of cardiovascular disease and Type 2 diabetes, according to the USDA.

Dairy

• Milk and dairy products provide calcium for healthy teeth and bones to prevent osteoporosis. The dairy food group contains foods with significant calcium content. Cream cheese, cream and butter, which contain little calcium, are not considered part of this group. Low-fat or fat-free products are the best choice or lactose-free products if you cannot consume milk. This group also contains potassium to maintain healthy blood pressure and vitamin D to help assimilate calcium.

Meat and Beans

• Meat and beans contain protein, which is digested into the amino acids necessary for the body's cells, tissue and organs. This group contains meat, fish and poultry, which should consist of lean and no-fat choices. It also encompasses dry beans or peas, nuts, seeds and eggs. The meat and bean group provides B vitamins -- niacin, thiamin, B-6 and riboflavin -- necessary for forming red blood cells and building tissue, and for the nervous system. This group also contains vitamin E, an antioxidant; magnesium, for building bones and releasing energy from the muscles; iron, to carry oxygen in the blood; and zinc, for the immune system.

Oils

• The oil group consists of fat from sources such as fish, nuts and vegetable oils. Choose cooking oils that do not contain trans fat and are low in saturated fat. Oils contain essential fatty acids and vitamin E, necessary for health, but they should be limited. Oil contains about 120 calories per tbsp.