Never mind the sugar—how much fat?

For most women, deciding if a food is healthy is much more about fat than sugar.

In fact, University of Iowa researchers found that even when women know a food is high in sugar, they don’t rely much on that information to judge its relative healthiness. Overall, women in two studies relied more on their perception of a food’s fat and fiber content than on its sugar and protein stats when deciding if a food was good for them.

That could spell trouble in the long term, researchers say, given the weight- and health-related problems associated with excessive sugar intake—namely, obesity and Type 2 diabetes.

“‘Fat is bad, fat is bad, fat is bad’ is pervasive in our culture,” says Marianne Rizk, a graduate student in the psychological and brain sciences department at the UI and the first author of two studies that examine women’s perceptions of food healthiness and a third that looks at women’s sensitivity to the portion size of unhealthy foods.

“I wasn’t surprised that people would rely on the fat content in terms of the healthiness of a food—the more fat, the more unhealthy it is,” she says. “That seems to make sense. But that same reliance was not there for sugar.”

Teresa Treat, an associate professor in the psychological and brain sciences department at the UI and co-author of the studies, says the results could be a response to an aggressive national nutritional campaign espousing the dangers of too much fat in one’s diet.

“Still, I too was surprised by the discrepancy between fat and sugar,” she says.

Surprisingly little is known about women’s perceptions of the relative healthiness of food, Rizk says, even though those perceptions could influence what women decide to eat and might be related to eating disorders or weight-related problems.

In response, Rizk and Treat developed a new assessment strategy in which women viewed photographs of 104 different foods, such as cake, carrots, broccoli, fried chicken, a banana, and gummy bears, and judged the healthiness of each food on a 200-point scale.

“We know the nutritional content of all the foods, so we are able to calculate how much each woman relies on different nutrients when judging food healthiness, such as fat, fiber, sugar, and protein,” Rizk says. “This allows us to get a sense of what healthiness ‘means’ to each woman.”

For example, “food healthiness” might be tied strongly to the fat content of food for one woman, related to sugar content for another, and linked to both fiber and protein content for a third.

Across two studies—the first involving 263 undergraduate women and the second, 169 community women—the researchers found that most participants relied more on fat than sugar when judging food healthiness. They also found women had a tendency to overestimate a food’s healthiness when both unhealthy and healthy nutrients were present—a spinach salad with rich dressing, for example.

In a third study, Rizk and Treat discovered that college-age women could discriminate between various small-to-moderate portion sizes of unhealthy foods, such as candy and French fries, but struggled as the portion sizes increased. That studied involved 272 participants who were asked to judge the healthiness of 124 photographs of unhealthy foods of varying size.

Treat says psychologists know that it is harder for people to perceive size as size increases, so the results aren’t wholly surprising.

“So, people are pretty good at distinguishing between small and medium sizes of foods,” she says. “They are not very good at distinguishing between large and extra large.”

The researchers suggest future public health campaigns highlight the significant influence of portion size and proper sugar and protein consumption.

“What Marianne has shown is women’s perceptions of healthiness are indeed related to nutritional composition and also to portion size, but not nearly enough in both cases,” Treat says.  “Thus, we currently are developing educational programs designed to help consumers better understand the roles of nutritional composition and portion size in food healthiness.”