Nutrients are compounds that provide the body with the components necessary to carry out metabolism, growth, reproduction and other body functions. The McKinley Health Center splits nutrients into two groups: macronutrients and micronutrients.
The three essential macronutrients are carbohydrates, proteins and fats. Carbohydrates are the body's primary source of energy. They are readily broken down into glucose, the fuel source used by all types of cells. The McKinley Health Center reports that carbohydrates also play important roles in waste elimination, intestinal health and central nervous system, kidney, brain and heart functions.
Protein is primarily used to build and repair tissues. The McKinley Health Center also lists carrying out immune function and acting as component in hormones and enzymes as additional functions. Protein can also serve as a secondary source of energy when carbohydrates are in short supply.
Fat is the nutrient that the body chooses to utilize for long-term energy storage. It provides a cushion for vital organs, maintains the characteristics of cell membranes and aids in the absorption of many micronutrients. Despite fat's bad rap, a minimum amount of fat is required for survival, the McKinley Health Center states.
The McKinley Health Center describes micronutrients as essential nutrients that are needed in much smaller quantities than macronutrients. They include vitamins and minerals. Micronutrients aid a variety of body functions and are best thought of as accessories to macronutrients.