Microwaving is a convenient way to heat food with ease and in short periods of time. But, do microwaves change the nutritional value of food?
Microwaving food does change the nutritional value of food by reducing its content. However, the nutritional value of any food is always reduced with any other method of cooking. In fact, cooking food in the microwave gets rid of less of some of the nutrients than other cooking methods such as baking or boiling.
In microwaves, unlike other methods, food is heated through electromagnetic radiation. The heat waves are changing electric and magnetic fields, this especially affects molecules that are polar, such as water. So, the polar molecules will flip around during the microwaving process to line up with the changing fields. This allows food to be heated equally from the outside like the inside. But, the air does not change when microwaving because it is composed of nonpolar molecules. Altogether, this reduces the nutritional value of food but not by much.