How is frying food bad?

Actually, it depends on the case. If you are talking for example frying food using "recurrent used" oils (such as in fast foods), this is really bad for you.

Oils contains unsaturated fatty acids. You see, the normal form of the double bond of this fatty acids is on the "cis" form. When altered (e.g. :due to high temperature when cooking) , it undergoes isomerism and change into "trans" form. This form of fatty acid is due to catalytic hydrogenation of oils. These are found in food such as cookies, candies, and fried foods (espcially french fries). When ingested by humans, "trans" fatty acids do not accumulate in our body, thus it circualtes all through out in the blood and can be vulnerable to lipid peroxidation.

Lipid peroxidation can cause free radicals which are harmful to our cells. These free-radicals can damage our tissues, which may cause cancer, inflammatory diseases, atherosclerosis, aging, and other cardiovascualr diseases.

That's why it is advisable to use oils w/ high saturated fatty acids when cooking because it contains less double bonds, thus less conversion of "cis" to :trans" fatty acid double bonds. Furthermore, once you have already used the oil in frying or cooking, you should already disregard it and use another if trying to cook another set of food.

Fried Food Bad

Deep frying anything qualifies it as drowning it in oil. Because oils/fats have the highest caloric density of any nutrient (9 calories per gram), deep fried foods supply a great deal of empty calories. Also, even if it is a healthy oil, once the body has received its requirements, the rest become empty calories.

Here is more info about essential fats:

http://www.spartafit.com/nutrition/essential%20fat...

Oil as such is not bad for your health, but is infact necessary for your body.

Oil which is not heated consists unsaturation (carbon-carcon double bonds). On frying (heating in general actually), these double bonds get hydrogenated and the oil becomes saturated. Such saturated oil is not good for the health.

The bad oils and the breading that is in a lot of foods as well as the carbs such as those in french fries and the calories too.

It's the oils, butter, margarine, fat, etc that are bad for you and clog the arteries. I "fry" things dry. LOL. I don't use any oils usually. If I need oil, I'll use olive oil. Its really good for you!

Well, in the frying process of carbohydrates acrylimides are formed which has been known to cause cancer...just like saccharin.

whatever u use to fry ur food remember one thing. frying is pretty closer to the term 'overcooking'. now, if u fry something or overcook something u partially kill the nutrients in it n that's clearly not good.

Too much grease,oil.cholestorol, building up fat aroud your arteries isn't a good thing.