Nutrition labels can be confusing. Experts say their information is often difficult to interpret, and that ingredient amounts are meaningless if not put in the proper context.
According to one researcher, nutrition labels are not only confusing but deceptive, particularly when it comes to trans fats, the unsaturated fats often found in junk food.
Eric Brandt, now a student at Case Western Reserve School of Medicine in Cleveland, did some investigating while still an undergraduate and found that even when labels indicated no trans fats, foods often contained them.
Using this research, he published a paper in the current issue of the American Journal of Health Promotion, calling for changes in the way trans fats are listed on labels. Experts agree that trans fats are a health hazard but believe there might be better ways to indicate their presence, and that changing regulations could have adverse effects on consumers.
"I looked more closely at the list of ingredients and found that a lot of foods that say they have no trans fats actually contain partially hydrogenated oils, which do have trans fat in them," said Brandt.
He said the discrepancy occurs because the U.S. Food and Drug Administration does not require manufacturers to list trans fats if they are present in amounts less than .5 grams.
Omitting that information, however, could pose a danger to consumers.
"Research has consistently shown that if you add up small amounts less than .5 grams over time, it can become a significant amount and can be harmful to health," said Brandt.
Current dietary guidelines recommend consuming no more than 1.11 grams of trans fats per day. Trans fats also tend to raise levels of "bad" cholesterol and lower the levels of "good" cholesterol.
"Trans fat is potently associated with inflammation, heart disease, diabetes and probably cancer," said Dr. David Katz, director of Yale University's Prevention Research Center in New Haven, Conn. "It is in a very literal sense a kind of slow poison."
But other nutrition experts say that while trans fats can be detrimental to health, there's no need to fear that consuming them will greatly increase the risk of cardiovascular disease.
Because of the FDA's current requirements, if a food contains .49 grams of trans fat, the manufacturer is permitted to list the amount of trans fat as zero.
"The current recommendation favors the manufacturers, because it is based on serving size," said Dr. Jana Klauer, a physician in private practice in New York.
She gave as an example the amount of trans fat for a bag of potato chips. There may be less than .5 grams of trans fat per serving, but a serving may be only five chips.
"The listing is misleading to the consumer in that they read zero trans fat on the label and unknowingly consume the trans fats," she said.
To more accurately reflect the amount of trans fat in food, Brandt believes it should be listed in increments of one-tenth of a gram. If, for example, there are .35 grams of trans fat in a food, the label should read .4 grams. If there are .34 grams of trans fat, the label should read .3 grams.
"The only time the amount should read zero is if there are .04 grams or less," said Brandt.
Other experts agree there should be changes in the way manufacturers convey trans fat amounts on their labels but suggest other ways of doing it.
"A better listing would be on the front of the package saying, 'This product contains trans fats. Trans fats raise cholesterol levels and may lead to heart attacks and stroke,'" said Klauer.
Ayoob said he believes that amounts less than .5 grams should be listed, but is also worries that new regulations would cause manufacturers to cut out trans fats entirely and replace them with substitutes, such as fully hydrogenated oil.
"I do not agree that there should be labeling for amounts less than .5 grams," said Joanne Ikeda, co-founder of the Center for Weight and Health at the University of California at Berkeley. "The reason is because trans fats occur naturally in a variety of foods such as meat and dairy products. If people eliminate these foods from their diets, it could result in deficiencies of certain nutrients such as calcium."
The FDA has required trans fat information on food labels since 2006. A spokesperson for the agency said since it hasn't yet seen Brandt's paper, it is too early to comment on it. However, the spokesperson also said it's difficult to confirm amounts less than .5 grams, which is why that became the rule.
Some nutritionists say that so far, the FDA's guidelines on trans fat labeling have been effective.
"Most food companies have made a concerted effort to eliminate trans fat from their products because they knew consumers are concerned about these fats," said Ikeda.
Regardless of FDA guidelines, experts recommend that consumers stay knowledgeable about what's in their food.
"They need to look at both nutrition facts and ingredients and be sufficiently informed about both to interpret them," said Katz.