Hint: Generally, we know that macro represents large or huge or abundant. Nutrients are substances which are present in our body which have an important role in our metabolism.
-Nutrients are substances which are used by living organisms to survive, grow and to reproduce. These are incorporated into cells for metabolic purposes and or it is excreted by the cells. Some of the nutrients are converted to smaller molecules while releasing energy by breakdown of carbohydrates, lipids and proteins.
-There are two types of nutrients and they are macronutrients and micronutrients. Micronutrient has its main importance in supporting metabolism. It is needed in very trace amounts but they are very essential for human metabolism. Examples of micronutrients are dietary minerals (trace elements, ions such as copper or iron or salts) and vitamins.
-Macronutrients are those nutrients which are required in large amounts to maintain body functions and carry out daily activities. These provide calories or energy. Because it is needed in our body in large amounts it is called macronutrients.
-Macronutrients are classified into three broad categories: proteins, carbohydrates and fats.
-The main chemical elements that humans or any other living organism consume in large quantities is carbon, nitrogen, hydrogen, oxygen, phosphorus and sulphur. They provide bulk energy. Water is also consumed in very large quantities.
-Some other macronutrients taken into considerations are calcium, sodium, magnesium, chloride ions.
-Macronutrients such as carbohydrates, proteins and fats are broken down, a large amount of energy released which is needed for the body unlike micronutrients. Fat can produce a food energy of about 38 kJ per gram.
Therefore, macronutrients are the nutrients which are essential for living organisms and because they are needed in large quantities, such nutrients are called macronutrients.
Calcium, sodium, potassium, magnesium and chloride ions are taken to be macronutrients because they are required in large quantities when it is compared with micronutrients. Micronutrients consist mainly of trace or ultra trace elements such as copper or iron ions.