The study, published in the medical journal JAMA Internal Medicine, found that giving vegetables certain descriptive labels caused more students and staff at Stanford University to choose vegetables during lunch — even though there was no difference in the way the vegetables were prepared.
The vegetables were labeled in one of four ways: basic, healthy restrictive, healthy positive or indulgent.
The basic description just listed the vegetable name, like corn or zucchini. The healthy restrictive category used words such as reduced-sodium corn or lighter-choice zucchini. Descriptions like vitamin-rich corn and nutritious green zucchini were used for the healthy positive. And indulgent was reserved for descriptions like rich buttery roasted sweet corn and slow-roasted caramelized zucchini bites.
Brad Turnwald, a doctoral psychology student at Stanford University and lead author of the study, found that making the labels indulgent increased the number of people who chose to put the vegetables on their plate, as well as the amount of vegetables consumed.
Vegetables labeled indulgently were 25% more likely be taken than basic-labeled. There was an even bigger difference in the numbers between healthy positive, healthy restrictive and indulgent. Thirty-five percent more people took indulgently labeled vegetables over healthy positive-labeled vegetables, and 41% more took indulgently labeled vegetables over those labeled healthy restrictive.
“We think that the indulgent labeling aligns more with people’s motivations,” Turnwald said. “That they’re looking for something tasty when they want to eat. And that’s why it works.”
The study was conducted over the course of an academic quarter at Stanford, in a large cafeteria serving about 600 people during weekday lunches. Research assistants counted the number of diners taking vegetables by dressing as members of the cafeteria staff. The amount of vegetables diners took from self-serve containers was weighed by actual members of the cafeteria staff.
“People taste what they expect to taste,” said Wansink, who was not involved in this research study. “If we think food is crunchy, we rate it as crunchy afterwards. So if you make food look more exciting or sound exciting, people are more likely to take it.”
Turnwald emphasizes that no matter the wording, the vegetable descriptions were always accurate.
“We’re certainly not trying to trick people into eating more vegetables,” he said. “What the labels did in this case was shift people’s attention to the indulgent and tasty characteristics of the vegetables, instead of focusing so much on the healthy components of the vegetables. No matter what condition it was, we were always making true statements about the vegetables.”
For Turnwald, changing mindsets through new labels is key to more people eating vegetables.
“We really need to think about this as a way to start changing the culture,” he said. “The way that we talk about healthy foods — it shouldn’t be so negative and so depriving and so focused on health. It should be focused on the flavor and the taste, because that’s how we talk about all the other foods that we know and love.”