Triglyceride-Simple Lipids: These are simple, moderate or pure. Their molecules are relatively large. Each molecule is synthesised by joining together one molecule of glycerol and three molecules of fatty acids through 'ester bonds'. That is why they are also called triglycerides. Ghee, oil, fat etc. are examples of unsaturated fats, whereas oils of peanut, mustard, sesame, sunflower etc, are unsaturated fats. These always remain in liquid state. 'Vaspati Ghee' is made by adding hydrogen separately to them.
Due to less amount of oxygen in them, their oxidation is more. Therefore, they release twice as much energy as carbohydrates. They are most important as stored food for energy. Most of their storage occurs in specialised adipose tissues.