Does microwaving food make it less nutritious?

OK, so a while back I’m going to heat up this old piece of pizza, so I stick it in the microwave. My Mom says, “you shouldn’t do that, it takes away the nutrients.” I’m thinking that it might take a couple away, but not enough to make a difference, and if it is enough to make a difference then I’m going to be pissed, because all that food I’ve heated was pretty much empty calories, I guess.

So that’s my question, does microwaving food make it less nutritious???

Just wanted to add something, as far as foods being nutritious, I know that raw food is supposed to have more nutrients. So I guess the revised question is, would that piece of pizza have been more nutritious if I’d eaten it cold or stuck it in the oven and not the microwave?

Um, no, I think I’m fairly safe in saying, “Heating up food in a microwave doesn’t take away the nutrients.” Does heating food up in a pot on the stove, or in the oven, take away its nutrients? No.

The thing about uncooked food being more nutritious has to do mainly with fruits and vegetables. When you cook fruits and vegetables in a pot of water, a lot of the vitamins go into the water, and if you dump the cooking water down the drain, you of course have just dumped all the vitamins down the drain.

However, AFAIK raw meat is just as nutritious as cooked meat. Actually, cooking meat may even make it MORE nutritious, for example, with a really tough pot roast. Cooking it tenderizes it so your digestive tract doesn’t have to do so much work. Ditto for fruits and vegetables, if you can steam them so the vitamins stay in.

Potatoes are very difficult to digest in the raw state. Raw bread dough is also difficult to digest. Ever tried to eat under-cooked bread (because you didn’t want to hurt the baker’s feelings :smiley: )and got a bellyache?

And cheese and tomato sauce remain pretty much the same substances whether you’ve warmed them up or not.

I understand where your mom is coming from, but, eh, sorry, she’s wrong. :wink:

Sheesh. [knocking self on forehead with hand] I just realized–she’s talking about the Evil Microwaves Sucking All The Nutrients Out Of Your Food, not “losing vitamins by boiling”.

Okay. Hot food is hot because its molecules are moving really, really fast. When you heat up a piece of cold pizza in the oven, it’s surrounded by the oven’s heat, and the oven’s heat is transferred to the pizza and make its molecules vibrate really, really fast. The pizza gets hot.

A microwave uses microwaves instead of gas heat to make food’s molecules start vibrating really, really fast. The end result is the same–the pizza gets hot. The evil microwaves do not suck the nutrients out of your pizza. Trust me. :slight_smile:

There are a few nutrients which will be broken down (“denatured”) by cooking or overcooking, but even then, the method of cooking (conventional or microwave) won’t matter much, just the final temperature. Plus, since your pizza was (presumably) already cooked once, and at a higher temperature than it’s going to get in the nuker, all those nutrients are already denatured, anyway. Go for it, unless you happen to really like cold pizza.

yes heating food will make it less nutritious. But then again pizza is not all that nutritious anyway and possible takes more micronutrients to break down then you get from it.

But a microwave is so…, so…, modern! It must be bad (apologies in advance, manny).

Actually, I believe cooking food does eliminate some nutritional value. Check out Cecil’s thread on why eskimo’s don’t get scurvy. Cooked food doesn’t have the same nutritional value.

If you check out [rul=]this site, it says that the most nutrients are lost from food at high, prolonged temperatures.

Vitamins and proteins are large, organic molecules. At high temperatures, they tend to degrade. which would make them less nutritious. With proteins, this is less severe, as they are probably broken down into amino acids by the body, but cooking can make them harder to digest. Vitamins can also be Soaking foods in waters or fats can render them less nutritious by leaching water soluble nutrients out.

You can see the effect of heat on organic molecules by cooking yourself a burger with ground beef. Notice: it turns from red to brown.

On the other side of the coin, not cooking foods (meats) is typically fatal. Anyone want my raw beef/chicken soufflé? I promise, you’ll die!

Since we’ve been cookign our food for a while (except, perhaps, in the more extreme climates where doing so is fatal), we’re fairly well adapted to it, so I recommend warming up your food.

Bon appètit!


People eat raw beef. Even if they did not rare steak is not hot enough in the center to kill off germs.

The steak example is probably not very fair example though. The outside of the beef gets cooked hopefully killing off the germs. The under cooked hamburger is what has caused the food posioning deaths I have heard about.

Chicken is pretty dangerous to eat raw but it is a very long way away from the instant death you describe.

And to echo Duck Duck, veggies in the microwave usually end up steamed.
This preserves a lot more nutrition (and keeps 'em crisp) than boiling them.

GASP!!! Sacrilege!!!

It’s got meat, fruits and vegetables, dairy, and bread in it. It sounds like one of the most nutritious dishes out there! :D:D