Macronutrients in our diet:

Cholesterol
Cholesterol is a waxy, fat-like substance produced mainly in the liver but can also be made by cells (except for red blood cells). The liver produces all of the cholesterol the body needs, but cholesterol is also found in animal foods, such as meats, poultry, fish, eggs, butter, cheese, and milk. (Plant foods contain no cholesterol.)

For transport in the blood, cholesterol associates with certain proteins to form lipoproteins. Cholesterol is present in the membranes of all cells, acts as insulation around nerve fibers, serves as a building block for certain hormones, and is needed for the formation of bile acids, which are required for the absorption of fats from the intestine.