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Microwave food

  1. May 24, 2005 #1
    Not sure if this is the right forum for this question (maybe I need some microwave theorists instead?) , but:

    a friend of mine was telling me about an article she read about microwave food being unhealthy for you. Apparently, living off a diet of microwave for too long, even though you are getting all the nutrients you need, is still very unhealthy.

    Can somebody back this up or disprove with scientific arguments? Thank you.
  2. jcsd
  3. May 24, 2005 #2
    Do you mean eating microwave food that has been pre-packaged and usually found in th frozen section or do you mean just using the microwave to heat up one's food. About the microwave dinners, they are always very high in sodium and usaully high in saturated fat, which is an unhealthy combination. I'm not sure about the actual microwave making the food unhealthy. Maybe someone can help?
  4. May 24, 2005 #3


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    In microwave cooking, the wavelength (12cm) chosen was one that is found to excite (increases kinetic energy) water molecules.

    So as the microwaves pass thru food in the oven, their energy is converted to heat. When you pop, popcorn in a microwave, it is heating the water in the corn kernel to a temperature where it bursts the seed coat. When you insulate your food (leaving the husk on sweet corn, or wrapping dehusked sweetcorn with paper towels) you will find that it cooks faster in the microwave.

    So try and heat up some ordinary dry paper towels (nothing else) in the microwave oven and see what happens.

    I don't know if there have been any rigorous studies to explore whether microwaves (wavelength of 12cm) alter the chemistry of other molecules in food. Perhaps someone else can help there..
  5. May 24, 2005 #4


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    What does this do? I've been warned against heating unusual things in the microwave, as it can be a fire risk.
  6. May 24, 2005 #5
    There are some concerns that plastics and other materials used in packaging of microwave foods may be absorbed into the food that we eat. The FDA says there is no need for concern. They also say...
    On one hand they say there is nothing to be concerned about and on the other they say not to use certain plastics and not to let plastic touch the food. There are probably regulations on what types of plastics can be used for use in a microwave. At one time there might not have been.

  7. May 25, 2005 #6


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    Other than the plastics issue, I really don't know of any reason why microwaving would be a problem. Are there any vitamins or other nutrients that are broken down by microwaves? That's about the only other thing I could think of that might be an issue, but I don't know the answer to that question.
  8. May 25, 2005 #7


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    I don't think it's the microwaving itself, or the containers which are the problem. All the recent health concerns here have just been regarding the ingredients. Loads of ready-meals have really high salt contents, and lots of saturated fat.
  9. May 25, 2005 #8


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    You'll find a lot of propaganda on the web, making all manner of wild claims. I did manage to find one site that seemed reliable - it's run by the Australian government, so their info is presumably legit.

    It seems the main concern was that vitamins, especially B vitamins, can be lost when you cook meat in the microwave. This was found to occur in studies, but is probably just due to meat being cooked in more water than is necessary. It is recommended that you drain your meat of any excess water before microwaving, in which case the vitamin content remains the same. Microwaving vegetables, on the other hand, seems to actually increase vitamin retention over conventional forms of cooking. This site also suggests that protein quality might be higher in microwaved meats than in conventionally cooked meats, because the decreased cooking time results in less oxidation. Here is the site:

  10. May 25, 2005 #9


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    Paper is not unusual. It is often used to wrap around food that you are heating.

    What happens when you heat paper in a microwave? Although the moisture in paper ranges between 4-10%, the temperature change upon exposing to microwaves in an oven, will be slight. You probably won't notice any difference.
    You may want to try this experiment again, after moistening the paper towel.

    The World Heath Organization has an excellent information sheet on microwave ovens and health.
    An exerpt "Food cooked in a microwave oven is as safe, and has the same nutrient value, as food cooked in a conventional oven. The main difference between these two methods of cooking is that microwave energy penetrates deeper into the food and reduces the time for heat to be conducted throughout the food, thus reducing the overall cooking time."
  11. May 28, 2005 #10
    CSIRO are very good research institution that do research in these genres, food, agriculture and biotech. I am a man for the good old wood fire oven, but having neighbours one has to make a compromise. Generally I have found "taste" to be different from traditional methods of cooking and conventional (stove, oven..). Obviously food is being cooked so there is chemical change and due to that one can assume a change in the nutrient content and nature, taste is also a pretty good indicator as our tastebuds react to several macronutrients and their relative concentrations would affect the general sensation which to my observation was the case.

    Although there are several loopholes in that observation, I would opt for not using the microwave to cook food but only to heat foods just for the taste factor. Evolution has made us like certain foods and dislike others, I go by the tongue rather than what is taught and told about nutrients, so phrasing it like one would hear in iron chef "let the tongue be your guide".
  12. Jun 9, 2005 #11
    So, in summary:

    1) Pre-made microwave meals are generally less healthy, and a diet based on these meals will have an unhealthy effect on your body.
    2) Certain plastics used to cover microwave meals can contaminate these meals when in direct contact with the meal.
    3) If sufficiently covered and nutrients aren't lost through loss of vapour, traditional cooking and microwave cooking lead to comparably healthy meals.
    4) Taste is also a good determinant for healthy food, and microwave food is simply less tasteful.

    Leading to more questions:

    2) I've the habit to cover my plate with another plate. Is there any reason why I shouldn't do this? It's much more economical/ecological not to have to throw away plastic coverage.

    4) I agree, although I think that heating food that has been cooked beforehand, has the same problem. That's where the phenomenon 'rubber chicken' comes from.
  13. Jul 7, 2005 #12
  14. Jul 7, 2005 #13


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    Hmm...if they're trying to compare 5 min in the microwave to 3.5 min steaming, I don't know how you can draw any conclusion at all! I tend to agree with the second comment there, that it might be more of an indicator that the best way to retain nutrients is to not overcook your food. I've never known the microwave to require more time than conventional cooking!
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