Macronutrients in our diet:

Fats and oils
Fats and oils belong to a group of substances called lipids. All fats are combinations of saturated and unsaturated fats.
Fats are vital for the proper functioning of your body. They are used to store energy, are required for the formation of the membranes of cells to keep their contents within, are converted to important hormone-like substances, and form triglycerides that provide a layer of insulation under the skin.
Since the body cannot manufacture all the types of fats it needs, certain ones must be obtained from foods and are called essential. In addition, dietary fat is needed to help the intestine absorb vitamins A, D, and E.