Fats are members of lipids. Like carbohydrates, fats are also made up of carbon, hydrogen and oxygen. However fats contain more carbon and hydrogen and less oxygen.

Fats are the richest source of energy. Fats are insoluble in water but soluble in solvents like acetone, and benzene. Chemically, fats are triglycerides.

One gram of fat on biological oxidation gives about 9.0 kcal (37 kilojoules) of energy. 

Sources of Fats

Animal sources: Ghee, butter, fish oil, meat, egg

Plant sources: Vegetable oil from the seeds of coconut, mustard, sunflower, safflower, milk, nuts, soya bean, cheese

Functions of Fats

  • Fats are the richest sources of energy. On biological oxidation, one gram of fat provide 37 kJ of energy.
  • Form structural components of cell cytoplasm and cell membrane.
  • Help in absorption of fat-soluble vitamins A, D, E and K.
  • Act as precursor of various hormones.
  • Can be stored for subsequent use by the body.
  • Sub-cutaneous fats serve as insulators in the body thus protecting it from cold weather and pressure.
  • Stored fat provides padding to protect the vital organs of the body from shocks.
  • Help in the synthesis of vitamin D and steroid hormones in the body.