SUNDAY, Sept. 16, 2012 (HealthDay News) -- People -- particularly women -- who read food labels while they grocery shop are thinner than people who don't, a new study finds. Women who checked nutritional labels weighed what amounted to nearly 9 pounds less than those who didn't.
The international team of scientists analyzed more than 25,000 observations on health, eating and shopping habits from the U.S. National Health Interview Survey. Among the data collected were responses about reading nutritional information in supermarkets -- if people did and how often.
"First we analyzed who read the nutritional label when purchasing foods, and then we moved on to the relationship with their weight," study lead author Maria Loureiro, of the University of Santiago de Compostela, in Spain, said in a university news release.
Nutrition labels tell consumers how many calories are contained in a food portion, as well as levels of sodium, fats, sugars, protein, dietary fiber and key vitamins and minerals.
The study found big differences between the people who read food labels and those who did not. Smokers, they noted, paid little attention to the nutritional information on foods.
"Their lifestyle involves less healthy habits and, as a consequence, it could be the case that they are not so worried about the nutritional content of the food they eat, according to our results," the researchers suggested.
People who live in cities were the most careful about reading food labels. People with high school and college educations also paid more attention to nutritional labels. Fifty-eight percent of men took the time to read labels, compared with 74 percent of women. White women who lived in cities read food labels most often, the study found.
"In general, the associated impact is higher among women than men. On average, women who read the nutritional information have a body-mass index [a measurement of body fat based on weight and height] of 1.48 points lower, whereas this difference is just 0.12 points in men," Loureiro said. "We know that this information can be used as a mechanism to prevent obesity.
"We have seen that those who read food labels are those who live in urban areas, those with ... high education," she added. "Therefore, campaigns and public policy can be designed to promote the use of nutritional labeling on menus at restaurants and other public establishments for the benefit of those who usually eat out."
The study was published in the journal Agricultural Economics.
Visit the U.S. Food and Drug Administration to learn more about food labeling and nutrition.