The shorter the wavelength, the higher the energy. Microwaves have relatively long wavelengths and, as a result, little energy. There is no evidence that eating microwaved foods is detrimental to humans or animals.
Microwaves are low-energy waves that, like visible light, fall within the electromagnetic spectrum .
They are non-ionizing waves and do not leave a residue. When food absorbs the energy in microwaves, ions in the food polarize and polar food molecules rotate, causing collisions. As far as we know, microwaves have no nonthermal effect on food. The only chemical and physical changes result from the heat generated. In fact, some of these changes are less obvious in foods heated in microwaves because the temperature rise is much faster than it is in regular ovens.