A small amount of fat is necessary for absorption and digestion of fat soluble vitamins like A D E and K. Also some amount of good cholesterol is essential as it is protective of the arteries and does not allow build up of plaque. However the key to remember is small amount just the amount that goes for tadka or on your roti. Also remember that fats can be got from better sources like olive oil, almonds, flax seeds, walnuts etc.