University Park, Pa. --- College age men who said they weren't inclined to eat low-fat foods were more easily influenced by false content labels than fat and calorie-conscious women in a recent Penn State study. Fed a low-fat, low-calorie lunch that was falsely labeled High Fat/High Calorie, the men reported less hunger and ate significantly fewer snacks later on than when they were fed the very same lunch correctly labeled Low Fat/Low Calorie. The women, on the other hand, ate the same amount of snacks regardless of the labeling or actual fat and calorie content of their lunch.
Women rated the lunches labeled Low Fat/Low Calorie significantly higher in "liking" and "satisfaction" than the men did. Both men and women, however, rated lunches labeled "Low Fat/Low Calorie" less rich even when the food was actually full fat - indicating that they really couldn't tell the difference.
The study director, Dr. S. E. Specter, assistant professor of nutrition, says, "Even though we expected the fat and calorie conscious females to be more responsive to written and verbal cues, it was the males who paid attention to the labels."
Specter notes that one reason the men probably were more influenced by the labels is because paying attention to fat and calorie content was a new behavior for them.
The College of Health and Human Development researcher will detail his study today (Nov. 16) at the North American Association for the Study of Obesity meeting in Charleston, S.C. His paper, "Examining the Relative Importance of External vs. Internal Cues Influencing Food Intake Behaviors in Response to Fat-Modified Foods," was co-authored by Julia A. Ello, Penn State doctoral candidate.
The study involved 21 males and 22 females and was representative of the typical young male who's not interested in low fat/low calorie foods and the young women who are. The study was also the first of its type to involve foods normally eaten in which the calorie content was halved in the low-fat versus the visually-identical high-fat lunch.
The subjects ate lunch in a Penn State food lab on four days where they were served either the full fat lunch or the visually identical fat-modified version. The lunch consisted of a turkey-and-cheese sandwich on a roll with butter accompanied by lettuce, tomato and dressing. On the side, they received chips, yogurt and a cola. Low-fat, low-calorie versions were made with a non-caloric butter-like spread, low-fat dressing and cheese, non-fat yogurt and fat-free chips.
Signs created by the food lab staff that said either "High Fat/High Calorie" or "Low Fat/Low Calorie" were placed on every tray. Chips and yogurt were supplied in commercial packaging with the original labeling. On the days that the participants were being presented with false labeling, the chip and yogurt containers were refilled by the lab staff with the opposite product.
In case the cues from the signs and packaging were missed, at the moment the lab staff members placed the lunch trays in front of the subjects, they said casually, "Well, looks like you've got the high-fat lunch today" or "Here's a low-fat lunch. Hope that's OK with you." Later in the day, at 4:45 p.m., the subjects returned to the food lab where they each remained in a secluded booth for one and a half-hours to study and snack, if they so desired, from a wide variety of foods.
Hunger reported in the afternoon did not differ for males, regardless of what they had for lunch. However, snack intakes for male but not female subjects were significantly higher after lunches labeled Low Fat/Low Calorie, regardless of actual fat/calorie content.
"The data suggest that cognitive cues such as label information can influence subjective ratings, including 'liking,' 'satisfaction' and hunger, for both genders," Specter says. "Label information, at one meal, also influenced the male subjects to shift their subsequent snack intakes.
"Female subjects, however, ignored the cognitive cues in the label information as well as the physiological cues from the calorie content of the lunch which was twice as high in the high-fat version. The women appear to have been relying on visual cues, such as portion size, guided by a preconceived view of how much they thought they ought to be eating," he adds.
EDITORS: Dr. Specter is at (814) 865-2138 or sespecter@psu.edu by email.