As attention to trans fat among health professionals and researchers has increased over the past decade, public awareness also has increased. In 2010, 64 percent of consumers state that they are trying to consume less trans fat (IFIC Foundation 2010 Food & Health Survey). People began to think about trans fat more often in part because the FDA has required the grams of trans fat, along with saturated and total fat, to be displayed in the Nutrition Facts panel since 2006.

As research increasingly solidifies scientific opinion that trans fat can have a negative impact on heart health, some have asked why trans fat ever ended up in foods in the first place.

During the 1960’s to 1970’s, agreement emerged among scientists and health professionals that saturated fat should be replaced with unsaturated fat to promote health. The major dietary source of saturated fat is animal fat, either inherently present in animal products (such as butter, milk, or meat), or as an ingredient in baked goods or fried foods. Unsaturated fat, though also found naturally in animal products, is primarily in the form of liquid oils processed from vegetables or nuts. Fats and oils give foods rich flavor, crispy texture, and other pleasing qualities. Solid fat, in particular, is more resistant to oxidation than liquid oils, so that packaged foods stored at room temperature remain palatable for a longer period of time. Therefore, replacing saturated fat with unsaturated liquid oils in certain packaged foods would have resulted in off-flavors and possible quality issues after just a short time on the pantry shelf. The process of partially hydrogenating unsaturated oils was developed in order to impart the taste, consistency, and freshness without the saturated fat that animal fat had provided. Because it is not saturated, research conducted at that time concluded that partially hydrogenated vegetable oil would be more “heart-healthy” than animal fats.

But science never rests. As scientists conducted additional studies, the research revealed that trans fat may be even less heart-healthy than saturated fat. Given these findings, health experts have been unequivocal in calling for dietary intake of trans fat to be “as low as possible.”  “As low as possible” takes into consideration the presence of naturally occurring trans fats in foods from dairy and beef.

Of course, “as low as possible” is not the same as “zero.” In the media and online, much attention has been focused on the fact that 0 grams of trans fat on a food label may not actually be “0.” Why the discrepancy? This calls for an explanation.
Technical limitations in food analysis methods impact the ability to quantify very small levels of nutrients in foods, and trans fat is no exception. Therefore, the FDA provides specific instructions to food manufacturers for declaring nutrients. For total, saturated, polyunsaturated, monounsaturated, and trans fat, amounts greater than 0.5 g are rounded to the nearest whole number. Amounts less than 0.5 g are rounded to the nearest 0.5 g, and if there is less than 0.5 g trans fat per serving, following FDA regulations, the label may state “0g on the Nutrition Facts panel.”

Sixty-eight percent of consumers (2010 IFIC Foundation Food & Health Survey) say they are actively using the Nutrition Facts panel as a valuable resource for making informed food choices and for determining the amount of trans fat in a food product. It is also important to remember that trans fat is only one tiny piece of a large heart health puzzle. Reducing overall calories and increasing physical activity to achieve a healthy weight, and increasing fruits, vegetables, whole grains, and non-fat dairy products, are other important steps individuals can take to improve health.