Do food-nutrition labels really help people choose healthier, lower-fat foods? Or does reading the "Nutrition Facts" box while devouring a bag of potato chips merely add to the guilty pleasure?
Nutrition labels really do take a bite out of fat intake, according to researchers at the Fred Hutchinson Cancer Research Center in Seattle, who will report their findings in the January issue of the Journal of the American Dietetic Association.
"We found a strong relationship between reading nutrition labels and eating less fat," says lead author Marian Neuhouser, Ph.D., R.D. "People who don't read labels get around 35 percent of their calories from fat, compared to about 30 percent for people who read labels." Nutrition experts recommend that consumers get 30 percent or less of their daily calories from fat.
"The difference in fat intake between label-readers and non-readers was evident even after adjusting for age, weight, sex, education, exercise, attitudes about diet, and everything else that relates to the way people eat," she says.
The study was co-authored by Alan Kristal, Dr.P.H., and Ruth Patterson, Ph.D., R.D. All are from the Hutchinson Center's Cancer Prevention Research Program, Division of Public Health Sciences.
Funded by the National Cancer Institute, this is the first study to examine the effect of nutrition labels on diet since 1994, when standardized "Nutrition Facts" labels were required by Congress to appear on nearly all packaged foods. The labels report standardized portion sizes, along with corresponding calories, total and saturated fat, sodium, cholesterol and vitamins A and C, among other dietary components.
For this study, researchers randomly surveyed a representative sample of 1,450 adults in Washington state who were asked about label use, food intake, exercise and smoking.
Label use overall was common; 80 percent of those surveyed said they read labels on packaged foods. Label reading was most typical among women, those who were college-educated or under age 35.
Strong predictors of reading labels included:
- believing in the importance of eating a low-fat diet (these people were 10
times more likely to read labels than those who did not believe a low-fat diet
was important);
- a strong belief that diet is related to risk of serious diseases such as
cancer or heart disease (these people were three times more likely to read
labels than those who did not think diet was related to illness); and
- being obese (these people did not read labels more often, but they were twice as likely to read the calorie and fat information than people of normal weight). Vitamin-supplement users and people who exercised regularly also were more likely to read labels.
However, even among the most motivated, health-conscious consumers, labels appear to be of limited value when it comes to calculating "%DV," or "percent daily value" for fat and other nutrients. "Percent daily value was supposed to help consumers select diets consistent with the Dietary Guidelines for Americans," Kristal says. "But we found that people just don't understand the percent daily value, so they don't use it. We clearly need to educate consumers about the interpretation and use of the percent daily value in meal planning."
To help simplify the use of percent daily value when selecting a low-fat diet, Hutchinson researchers have developed the "5-10-20" rule:
- 20 percent is the recommended maximum %DV for fat in a main-course dish;
- 10 percent is the maximum %DV for fat in a side dish, snack or beverage; and
- 5 percent of %DV for fat is a healthy food choice.
According to the researchers, one of the best uses for food labels is to uncover "hidden" fat in items such as crackers or cookies, which can vary widely in fat content from one brand to the next. "One box of crackers will have 5 grams of fat per serving while a similar type on the next shelf might have only half a gram. I think nutrition labels are most useful for comparison shopping to help people select foods lower in fat," Kristal says.
The bottom line, says lead author Neuhouser, is that people who are most successful at eating a healthy diet also use nutrition labels. "People who want to lower their fat intake should begin by reading food labels so they become familiar with the nutrient content of the foods they eat. If people are really motivated to lower their fat intake, nutrition labels can really make a difference," she says.
Journal
Journal of the American Dietetic Association