In short, this method of cooking may just be the healthiest. There are a plethora of reasons why but the main reason is how steaming works. All it needs is water and then it allows the steam that is manifested from the water to cook the foods. So, what this means is oils will never need to be used. As opposed to foods and vegetables that are cooked in oil and butter, this will yield much healthier results. Additionally, steaming helps to conserve the vitamins that some foods possess. You have heard it a million times that vitamins and minerals are essential to your health, so this makes sense.