Stealthy leads to healthy in effort to improve diet, Stanford study shows

STANFORD, Calif. — How do you get college students to eat better? A new study from the Stanford University School of Medicine suggests that a “stealth” strategy of raising the students’ awareness of environmental and social issues related to food can persuade them to eat more veggies and less ice cream.

The study will be published in the May issue of the American Journal of Preventive Medicine.

“This is a novel strategy, and we believe it is an important new direction to pursue,” said senior author Thomas Robinson, MD, MPH, professor of pediatrics and of medicine at the School of Medicine and director of the Center for Healthy Weight at Lucile Packard Children’s Hospital. “When people get involved in social movements, it changes their behavior more dramatically than what we’ve seen with more cognitive-based approaches.”

“Stealth interventions” are a new approach to an old problem: how to help people eat better and exercise more. The traditional approach used by physicians and health educators — urging people to make healthier choices because it’s good for them — has met with limited success, as evidenced by the skyrocketing rates of obesity in this country, said Robinson, who is also the Irving Schulman, MD, Endowed Professor of Child Health.

He began looking for other, more effective strategies several years ago, and wanted to explore whether he could tap into the zeal that surrounds social movements to help people to make healthier choices for a greater good, rather than for their own personal benefit. For instance, one way to curb the effects of global warming is to eat more fruits and vegetables grown locally and cut back on meat and processed foods that are transported over long distances. Although their primary motivation may be to help the environment, the person who adopts these new behaviors will end up eating a more nutritious diet.

And that’s where the “stealth” concept came in, said Robinson. The intention is not to deceive people into eating better or getting more exercise, he said. Rather, it is a way to “tap into the deeper needs and desires of the participants ? what we refer to as intrinsic motivators ? while improving their health as a side effect.”

To put the stealth strategy to the test, the study authors studied Stanford undergraduates who took a “Food and Society” course the researchers taught during the winter of 2009. The course focused on food-related social and environmental issues, rather than the health or nutritional aspects of food and eating. Students read and discussed sections from popular books ? including The Omnivore’s Dilemma, Fast Food Nation and The Ethics of What We Eat ? in addition to viewing Super Size Me and similar documentaries. They also were assigned to write and submit an opinion piece for publication, and work in small groups to create a brief YouTube video advocating some type of behavior change involving a food-related social issue.

For comparison, the researchers also tracked the students enrolled in three other health-related undergraduate courses at Stanford ? focusing on health psychology, community health and obesity ? that were taught the same quarter.

At the beginning and end of the quarter, students in all four classes were surveyed about their eating habits. The results showed that students in the “Food and Society” course were eating more vegetables and fewer high-fat dairy products, high-fat meats and sweets by the end of the course than they were at the beginning. The comparison students, however, reported no improvement in dietary habits and were eating fewer servings of vegetables at the end.

The students in the “Food and Society” course also felt more strongly about the importance of the environment, animal rights and the need for a healthy diet at the end of the quarter than did the students in the comparison classes. The researchers acknowledge that the students in the “Food and Society” class were likely to be more open to the environmental and social messages ? they had chosen to take the course ? but the four groups of students did not differ in their eating or attitudes at the beginning of the quarter, and the authors said the strategy to improve healthier behavior could be tailored to different issues.

Eric Hekler, PhD, the study’s lead author and a postdoctoral scholar at the Stanford Prevention Research Center, said the improvements made by the Stanford students show why it’s important for health researchers to think more broadly about effective ways to encourage behavior changes. “It seems like we don’t often enough think about our audience,” he said.

Getting young adults to establish healthy habits is important, Hekler said, because many of those habits will persist well into adulthood. Because people in this age group are at high risk for gaining weight and the beginnings of weight-related heart disease, he said it’s crucial to come up with more effective approaches for reducing those risks.

“This approach looks very promising,” Robinson said. “There are a lot of reasons why we believe the stealth interventions will produce longer-term, more sustained effects that are of a greater magnitude than other strategies that have been tried in the past.”

Robinson is employing similar strategies to boost exercise among children and adolescents, such as offering afterschool ethnic-dance classes for adolescent girls, and encouraging youngsters to reduce the amount of energy they consume by walking and biking to activities rather than being driven in a car.

He and the study’s other co-author Christopher Gardner, PhD, associate professor of medicine at the Stanford Prevention Research Center, have also submitted grant proposals for longer-term studies of the stealth strategy.

There was no outside funding for the study. Hekler’s involvement was supported by a grant from the National Heart, Lung and Blood Institute.

The Stanford University School of Medicine consistently ranks among the nation’s top medical schools, integrating research, medical education, patient care and community service. For more news about the school, please visit The medical school is part of Stanford Medicine, which includes Stanford Hospital & Clinics and Lucile Packard Children’s Hospital. For information about all three, please visit

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