At what point is the amount of cholesterol and trans fat required to be listed on labels? Many foods list the amount as "0," but the ingredients indicate the food must contain some.
You're right -- many foods have small amounts of cholesterol, trans fat or other nutrients per serving, but the U.S. Food and Drug Administration, which sets the rules for food labels, allows them to round down. That usually works just fine. But if you eat more than one official serving at a sitting, or if you often eat several different foods that aren't truly cholesterol- or trans fat-free, sometimes those "zeroes" can add up.
The official rules on rounding for all nutrients are online at http://www.cfsan.fda.gov/~dms/2lg-xh.html. For the nutrients you asked about, cholesterol is less likely to be fuzzy because it's measured in milligrams rather than grams. Any food with two or more milligrams of cholesterol per serving can't round down to zero. Dietary guidelines suggest limiting dietary cholesterol to 300 milligrams or below, so, if you're keeping track, you probably don't have to worry too much about foods containing less than 2 milligrams.
However, trans fat is measured in grams -- 1,000 times larger than milligrams. Foods with less than a half-gram (500 milligrams) of trans fat can round down to zero on the Nutrient Facts label. As you guessed, the trans fat in two or three servings of a food labeled as "zero" trans fat could add up quickly.
In 2003, the FDA estimated adults consumed an average of 5.8 grams of trans fat per day. Consumers are advised to limit trans fat as much as possible, but with the rounding rule, that can be difficult.
For clues, take a look at the ingredients. The terms "shortening" or "partially hydrogenated vegetable oil" indicate the product contains at least some trans fat. If you want the nitty-gritty details, try doing a search in the U.S. Department of Agriculture's National Nutrient Database (http://www.nal.usda.gov/fnic/foodcomp/search/). Some foods include the amount for "Fatty acids, total trans" under the detailed "Lipids" listing. It's worth a look if you're curious about exact amounts.
One more note on cholesterol: Only foods containing animal-based ingredients (dairy, eggs, meat or fish) contain any cholesterol at all. But even non-animal-based foods, such as those with palm or coconut oil, can contain high amounts of saturated fat, which actually has more of an effect on blood cholesterol levels than foods that contain cholesterol.
Chow Line is a service of Ohio State University Extension and the Ohio Agricultural Research and Development Center. Send questions to Chow Line, c/o Martha Filipic, 2021 Coffey Road, Columbus, OH, 43210-1044, or firstname.lastname@example.org.
Editor: This column was reviewed by Julie Shertzer, registered dietitian and program specialist for Ohio State University Extension in the Department of Human Nutrition, in the College of Education and Human Ecology.