Food contains a variety of nutritional components that can be categorized by macronutrients and micronutrients. Macronutrients are nutrients needed in large amounts that provide calories or energy for growth, metabolism and other functions in your body. The macronutrients include carbohydrate, fat and protein. Micronutrients, such as vitamins, minerals and antioxidants, are involved with cellular and chemical processes in your body. Deficiencies or excesses of nutrients can increase your risk of adverse medical conditions.
Carbohydrate is the macronutrient you need in the largest amount to supply your body with energy. Carbohydrate provides 4 calories per gram. The United States Department of Agriculture recommends you consume between 45 and 65 percent of your total dietary calories from carbohydrates. Carbohydrate foods consist of starches, sugars and fibers. Starches include whole grains, such as wheat, rye, barley and corn. Sugars include glucose, fructose, galactose, lactose, maltose, sucrose and other sweeteners. Carbohydrates and sugars are broken down during digestion and converted into glucose that your cells and tissues use for energy. Dietary fibers are not digestible. Soluble fiber can help you reduce blood sugar and cholesterol levels, whereas insoluble fiber can help you have regular bowel movements.
Dietary fat is a macronutrient needed for energy, cellular membranes, hormone production and absorption of fat-soluble vitamins. Fat provides 9 calories per gram. The United States Department of Agriculture recommends you consume between 20 to 25 percent of your total dietary calories from fat. Monounsaturated and polyunsaturated fats found in olive and vegetable oils, respectively and omega-3 fatty acids found in fish and nuts, are healthy fats that may reduce your risk of heart disease. Unhealthy fats include saturated fats found in animal products, such as meat and dairy, and trans fats that are industrial processed and used in frying or baking. Unhealthy fats increase your risk of heart disease.
Dietary protein is both a calorie source and provides amino acids to build proteins in your body for growth, maintenance and repair of cells and tissues. Protein provides 4 calories per gram. The United States Department of Agriculture recommends you consume between 10 and 35 percent of your total dietary calories from protein. Protein quality depends on its ability to provide nitrogen and up to 20 amino acids. Proteins from animal products, such as meat, poultry fish and dairy, contain all 20 amino acids, whereas proteins from plant products, such as legumes, nuts, grains and vegetables, may need to be combined with proteins from other plant products to enhance the quality of your protein intake.
Micronutrients include vitamins, minerals and antioxidants needed in miniscule amounts to produce enzymes, hormones and other substances for growth and development. Deficiencies can cause medical conditions, such as blindness or scurvy. Animal products are sources for micronutrients, particularly vitamin B12, calcium and iron. Plant products are sources for most micronutrients, especially vitamins A, C and E and phytonutrients.
- McKinley Health Center University of Illinois at Urbana Champaign: Macronutrients: The Importance of Carbohydrate, Protein and Fat
- United States Department of Agriculture: Dietary Guidelines 2010: Carbohydrates
- Mayo Clinic: Dietary Fiber: Essential for a Healthy Diet
- United States Department of Agriculture: Dietary Guidelines 2010: Fatty Acids and Cholesterol
- Harvard School of Public Health: Fats and Cholesterol: Out with the Bad, in with the Good