Why is vegetable oil to be avoided? Is it because of their Omega 6 content? And does this mean that fried food is to be avoided too?
Back in the good old days, food was fried in animal fat, normally beef tallow or lard. Then they started used "healthy" fats like Crisco and corn oil, now canola and safflower.
Omega 6 is inflamatory and it probably one of the most damaging components of the modern diet, after right after sugar and gluten. It became popular due to a misguided fear of saturated fats, as they were blamed for the damage caused by trans fats. O6 is an "essential" fatty acid, which just means that we need a little bit in our diet. However, we get a lot of it, about 20 times too much. Cooking with O6 oxidizes the fragile fats creating cancer causing free radicals.
Fry your food in saturated fats that don't oxidise. Any naturally solid fat will work. Butter, coconut oil, beef tallow, lard, drippings, etc, will work for frying. Virtually no restaurant in the western world uses these fats for frying anymore so avoid all fried foods you don't cook yourself.
Edit: I should mention hydrogenated fats. These are artificially hardened fats like crisco and margaine. These are evil due to their trans fat content and everyone now agrees that these should not be used anymore. Instead they've been replaced by a new type of fat called Interesterified fat. It turns out that there are issues with this fat that may be just as bad as the trans fats they replace. http://www.sciencedaily.com/releases/20 ... 131545.htm