When nonstick cookware is not used, usually a lot of oil or similar liquid is added to the food, so that the food does not adhere to surface of the pan or utensil used for cooking the food. However oil is expensive, and there are many health related associated with cooking food in oil.
It is not possible to completely remove all the oil from the food after cooking and some of the oil is consumed by the person who will eat the food. The oil has fat which can result in weight gain, causing associated problems like diabetes, heart attack and arthritis. To shed the fat, the person has to spend more time exercising. Using oil can be messy, as oil stains are difficult to remove , and cleaning the oily utensils will take more time.