Fire was discovered thousands of years back by our ancestors and we learned to cook our food in fire and eat them. But now doctors are telling if you can eat raw salads or cook food without fire, you can impart more goodness of the food intact.
Heating destroys many of the nutrients in vegetables. The bottom line is if you avoid cooking in fire you get more vitamins and minerals in your diet. By reducing the time you spend on cooking you can actually save energy and stay healthier.