I actually don't use much oil to cook with.  Instead I tend to poach in broth and most of My Baked Goods just don't require the addition of oil, as the Whole Foods I use bring with them their own oils!  When cooking, drizzling the cool oil on your meal after it's cooked is a more healthful and delicious way of eating it.  Even good oils are also a partial food, and anytime we can avoid heating oil it's best to do so, as heating oils will begin to break them down, thus creating the damaging Free-Radicals that course through our bodies requiring all those Antioxidants to fend them off.

So, Oil is Fat and Fat is generally Good, but some Fats are better than others and are also better used and consumed in certain ways. Eating Fat Does Not MAKE you Fat!  All this Low-Fat Garbage that is being Pushed is just another Horrible Blunder of Misguided Mis-Information!  Thanks again to Big Agri-Business many of the predominately used Fats are Literally Toxic.  When the Soybean and Cottonseed Industries discovered their Chemically Engineered Trans-fats could extend the shelf-life of most processed foods, they began to push their Deadly Trans-Fats and demonized Natural Saturated Fats with their massive Ad Campaigns, all in order to take over the market, and that they did!  Now, 60 or so years later we are dealing with the diseased, residual affects they've had on our health.  The re-evaluation of old studies, as well as New Research, shows No Correlation between Blood Cholesterol obtained from Natural Plants and Animals and Atherosclerosis!  You can thank Polyunsaturated Oils, Sugar and Refined Carbohydrates for our Heart Disease and rampant Diabetes issues.  Now we are also beginning an epidemic of Fatty Liver Disease because of these same 'Foods'.  The excess Carbohydrates are sent to the Liver where they're converted into Triglycerides and stored there as Fat.  Excess Sugar can also bond with Proteins or Fats and create Rogue Molecules, known as AGEs...Advanced Glycation Endproducts, which, like the Free-Radicals wreck havoc on our bodies. 

Here's a brief breakdown of fats as we understand them today:  First of all, did you know that our Human Breast Milk contains more Cholesterol than almost any other food?  More than 50% of it's calories are Fat, mostly Saturated, and are essential for Brain Health Development and Growth.  Fats carry our Fat Soluble Vitamins and Minerals into our Tissues and Bones.  We NEED Fats to survive.  Saturated Fatty Acids make up 50% of our Cell Membranes.  They help keep our Bones healthy by allowing Calcium to be absorbed into them and they escort the Fat Soluble Vitamins into our Organs.  Fats allow the body to make Hormones, protect our Digestive Tract and Liver from Toxins, and surrounds our Heart Muscle.  Saturated Fats also allow better Utilization and Retention of the Essential Fatty Acids.

Fats are made up of a combination of Short, Medium and Long (carbon) Chain Fatty Acids, although we classify them as one or the other depending upon their makeup.

Saturated Fats are called Saturated because they hold all the Hydrogen Molecules they can.  Monosaturated fats are missing one pair of Hydrogen Molecules and Polyunsaturated Fats are missing two or more Hydrogen Molecules.  Wherever a Hydrogen Molecule is missing it creates a weak link in the chain and becomes susceptible to Oxidation and Free-Radical Damage.  When we eat them, these Free-Radicals are transported into our bodies causing Immense Cell Damage on every level and pass straight through the liver. These Unsaturated Oils are Oxidizing and often already Rancid while on the supermarket shelf.  You don't know this because they are Highly Processed, Bleached and Deodorized.  When manufacturers 'Hydrogenate' an oil, they process it with Chemicals and Pressure in a way that adds Hydrogen Molecules so that it will have a longer shelf-life (and we're talking years!).

Saturated Fats usually come in the form of Butter, Ghee (basically butter with the solids removed by heating), Animal Lard or Tropical Oils, such as Coconut and Palm.  They are Highly Stable, even when heated and are usually the only oils I heat.  Coconut Oil is even a wonderful source of Medium Chain Fatty Acids that your body converts to Energy and has been proven to Promote Weight Loss.  As a matter of fact, years ago, farmers fed their livestock Coconut Oil hoping to fatten them up and had dismal results!  Now, instead they're fed Corn and Soy (genetically modified to boot)!

Monosaturated Fats are found in Nut, Avocado and Olive Oils and are Moderately Stable so they can be heated occasionally.   However, I prefer that heating them be kept to a very minimum in my life.  I prefer to use these oils mostly cold as dressings and condiments.

Polyunsaturated Vegetable Oils should never be heated or even consumed as they become Rancid and Oxidize Easily causing those Monsters mentioned earlier:  Free-Radicals.  These Compounds are missing an Electron so they must steal one from a Healthy Cell, causing damage to Tissues, Organs and Blood Vessels!  These Oils literally oxidize in our bloodstreams.  Heating these Oils also produce Chemicals called Polymers.  These Oils have been shown to Block Thyroid Hormone Secretion which is needed to convert Fat to Energy, as well as a myriad of other life sustaining functions! 

These Polyunsaturated Oils that are so Predominately used in Processed Foods provide too much Omega 6 Fats in our diet and are the Root Cause of our Imbalance of the Essential (meaning we must get them from our diet) Omega 6, 9 and Omega 3 Fatty Acids.  That's why you keep hearing to take Omega 3 Supplements!  Because everybody's intake of Omega 6's are so high!  This imbalance has been associated with many issues from Blood Clots, to Violence, ADD, BiPolar Disorder, and Depression!  (Kinda makes you wonder about another one of America's addictions: Anti-Depressants, hmmm?)

Needless to say, we don't use Polyunsaturated Oils such as Corn, Soy, Safflower, Canola or Cottonseed in my house!  Keep in mind also that these Highly Profitable Crops are the most Genetically Altered with their effects on our Health Unknown and some are even Toxic before they are processed into Oil!  For instance, ever wonder what a Canola is?  Canola Oil comes from the Rapeseed which has been Genetically Modified to reduce the Toxic amount of Euric Acid contained in the Seed.  The World is duped once it's renamed.  These Solvent Extracted and Expeller Pressed seed-based Oils are mostly Polyunsaturated.   Also many Seeds are not only Toxic before they're processed, but naturally they contain an Enzyme Inhibitor specific to Humans and other Mammals.  This is how Nature assures that the seed will travel through the Digestive System in tact and go on to propagate in the soil, or not be consumed at all because it makes you sick!