system
Given the following post, respond as if you're commenting on Reddit:
human
Do microwaves leave residual changes to molecules after heating?

Have a coworker who claims microwaves have a residual impact on the molecules in food and this is what causes microwaved food to taste worse than oven-baked food.

I've been puzzled by this since from what I know microwaves just excite water molecules and cause them to heat their surroundings. Yet he claims this changes the molecules in minorly-unhealthy ways.

He also claims the effect of microwaves on food aren't understood, something which I am incredibly sceptic of in this day and age with all the nutrition agencies around the world. 

So my question is: do microwaves have any residual effect on food beyond the heat from excited water?
gpt
No. Microwaves aren't energetic enough to be ionizing, they don't cause any other changes than conductive heating or radiatiative heating with IR (that is, grilling). Note that this is a feature of the individual photon energy, i.e. it doesn't matter how high you turn up the microwave because that increases the amount of microwaves hitting the food but not the energy of the individual microwave photon. This is the same reason why Wi-Fi (same micrwave spectrum) doesn't cause cancer.