Q. If you reduced omega-6 fats in the diet, wouldn’t that create another type of fat deficiency?

A. No, it would be very hard to create an omega-6 fat deficiency (linoleic acid), even on a low fat diet! It’s similar situation as dietary sodium.  It’s a nutrient that our bodie's require, but eaten in excess, is a problem.  Keep in mind that the omega-6 fatty acid, linoleic acid,  occurs naturally just about in every food. 

For example, just two slices of unadorned whole wheat bread provides an adequate amount of omega-6 fat.  Also, Stephem Cunnane, a Canadian scientist reported that  the original basis for figuring out how much omega-6 fat we need was greatly exaggerated, in part because of limited technology and a study-design error, which together amplified the estimated requirement for linoleic acid.

Omega-6 fat consumption should be limited to 2200 to 6600 milligrams per day, which is the amount you find in two teaspoons of a typical margarine.  This is in accordance to  guidelines published by a committee of scientists from the International Society for the Study of Fatty Acids and Lipids, (ISSFAL).Currently,  Americans currently eat two to six times of that recommendation.

Sources:
Cunnane SC. Problems with essential fatty acids: time for a new paradigm? Prog Lipid Res. 2003 Nov;42(6):544-68.

Simopoulos, Artemis P., Leaf, Alexander, Salem, Norman, Jr
Workshop on the Essentiality of and Recommended Dietary Intakes for Omega-6 and Omega-3 Fatty Acids
J Am Coll Nutr 1999 18: 487-489