fish oil's

I know Dr. Eric Serrano and Poliquin use large amount’s of fish oils to help athlete’s lean out.
They both say to begin to see results from fish oil to use a minimum of 9-15 grams.
MY ? is, is there a point where large amounts of fish oils hurt your weight loss goals.

Has any one else used large amounts of fish oil to lean out. How many Grams.
thanks