People who closely eyeball nutrition labels tend to eat differently from less-discerning diners in one key regard, according to research from a University of Illinois expert in food and nutrition policy and consumer food preferences and behaviors.

Although users and non-users of nutrition labels eat roughly the same amount of food, the two groups diverge when it comes to the quality of the food they eat, a new paper co-written by Brenna Ellison, Illinois professor of agriculture and consumer economics, noted.

“Research has often concluded that people who use nutrition labels eat better, but we don’t necessarily talk about what 'better' means,” Ellison said. “Is it eating less food, or is it eating better food? This study looks at people’s plates and considers both what they selected to eat and what they actually ate in an effort to determine which difference (volume or quality) is occurring.”

To examine the relationship between label use and food selection, servings and consumption, Ellison and co-author Mary Christoph of the University of Minnesota combined survey and photographic data of college students' lunch plates at two different university dining halls. Food selection, servings and consumption were assessed using digital photography -- a method with strong reliability for validating portion sizes compared with weighing food and visual estimation.

“In terms of measuring and evaluating the plates, we had students who built their own plates because it was a self-serve dining environment,” Ellison said. “Diners were only eligible if they were just sitting down to eat. It couldn’t be someone who was halfway through their meal, which would misrepresent what they were eating and skew the results.”

Based on the meals assessed, the quantity of foods served and consumed were roughly similar between the two groups. There were, however, distinct differences in the types of foods plated and consumed within the federal government's MyPlate food categories between those who tended to read nutrition labels and those who didn’t, the researchers found.

The results indicate that a greater proportion of nutrition label users select more fruits, vegetables and beans and fewer potatoes and refined grains compared with non-label users. Additionally, fewer label users selected fried foods and foods with added sugars, Ellison said.

“We find that it’s more about the types of food rather than the quantity of the food,” Ellison said. “The amount of food between label users and non-label users was roughly the same amount. It’s the differences in quality that are more prevalent than the sheer amount of food selected.”

Using digital photography also provided a more objective assessment of food selection, servings and consumption compared with self-reporting, because “you don’t have to rely on students remembering how much of each food they ate,” Ellison said.

“That’s one big advantage to this study," she added. "Another one is that diners did not interact with our data collectors until after their plate was built. So, our data collection methods shouldn’t have affected what they chose. For example, people weren’t picking more salad because they knew there was going to be a picture taken of their plate.”

Participants were further surveyed on socio-demographic and behavioral variables -- such as gender, body mass index, exercise frequency and nutrition education -- to better assess the possible link between label use and food selection, servings and consumption, according to the paper.

Doctors and dietitians often recommend that people examine nutrition labels to improve food choices, but choice does not always translate to consumption. Furthermore, evidence on the effectiveness of labels is mixed, and few studies can identify how labels actually influence behavior, Ellison said.

“Previous research has focused on portion control for weight loss or weight management -- generally eating less -- but more recent research indicates this may not be the most effective message. By eating less, consumers may feel deprived or even ‘hangry,’ which can make it difficult to sustain long-term dietary behaviors,” she said. “Newer research indicates that eating less of certain types of foods, rather than all foods, may matter more.”

Although the results show label users and non-users eat differently, the implications of the research suggest that there may be a need for greater consumption of fruit, vegetables, beans, whole grains and low-fat dairy among both groups.

In addition to posting labels, Ellison said dining facilities may want to increase offerings of nutrient-dense foods (whole grains and vegetables, for example) or consider product reformulations that creatively incorporate these foods to encourage healthy eating behaviors.

Ellison noted, however, that the study’s findings should still be interpreted cautiously, because the conclusions are based on only one meal.

The paper will appear in the Journal of the Academy of Nutrition and Dietetics.