“Q: How can a product with partially hydrogenated oils say it contains no trans fat?

A: Through a process called fractionation, manufacturers can now eliminate most of the trans fat from partially hydrogenated oils. So some such foods no longer contain trans fats. But in other instances, it’s just a labeling technicality, since the FDA allows food manufacturers to label any product “trans fat-free” if it contains less than half a gram per serving. If you eat a couple of helpings of a food that contains .49 grams of trans fat per serving, you could quickly wind up with more than the two-grams-per-day limit recommended by the American Heart Association. So it’s important to check the label for partially hydrogenated oils and steer clear when possible.“

Source: Liz Applegate, “Runner’s World”, February 2007 Volume 42 Number 2, p50