Unless you’ve been living in an Afghan cave for the last few years (or working for a processed food manufacturer), you know that trans fats are the root of all evil. The FDA now requires trans fat contents to be reported on food labels, so it should be pretty easy to avoid them.
However, there is a loophole: food packagers are allowed to round trans fat measurements down to the nearest gram. So, a food that contains .4 grams of trans fat per serving can round down and report 0 grams. It’s actually slightly worse than this; the FDA also allows a 20% margin of error on measurements, so a food with .6 grams could be adjusted to .48 grams (the 20% margin), and then rounded down to 0. In order to tell if the food actually has trans fat, look for any partially hydrogenated oils in the ingredient list.
I pulled a jar of Skippy peanut butter off the shelf – notice the 0 grams of trans fat listed and the partially hydrogented vegetable oils in the ingredients. Also notice the misleading message on the front of the jar NO TRANS FAT. The small print right below says per serving.
So it seems that as long as reported portion sizes are small enough, food manufacturers can report just about anything has being free of trans fats. In fact, the idea of intentional manipulation of reported portion sizes has been raised by a number of sources including Ray Kurzweil’s Transcend: Nine Steps to Living Well Forever (which I like very, very much and intend to review in a future post).
Although this sounds very plausible – and appeals to my internal conspiracy nut – I hadn’t seen any actual examples of this manipulation, so I thought I’d go find an example. Should be pretty easy – just find a food reporting the use of partially hydrogenated oils but 0 grams of trans fat, and then find that same food’s label from several years ago before trans fat was reported (before the strong motivation to reduce reported portion sizes). To my surprise, I couldn’t find any. It turns out that the FDA regulates portion sizes for food categories, and the manufacturers don’t have enough leeway to really do any significant manipulation. Oops!
So, there are loopholes when it comes to rounding and making claims based on that rounding. (By the way, this isn’t limited to trans fat. Gluten, alcohol, and other food substances are all subject to this same reporting guideline.) However, it seems that the intentional manipulation of portion sizes is just a myth.