How one recent college graduate got kids to eat better, and changed his own life too.

"Guess what I had for breakfast?"

As the "health coordinator" in an overcrowded school in a poor Brooklyn neighborhood, Benjamin Spoer fielded that question a lot. For two years, his job at Abraham Lincoln High School was to help its 2,500 students take responsibility for their own health — to steer them toward exercise, good nutrition, and other habits that ward off chronic illness.

 That's a hard sell for many American teen-agers, even in upscale neighborhoods where the message is reinforced by organic-food stores, personal trainers, gym classes, and achievement-oriented families. In a rough New York neighborhood, though, most of the students' daily experiences, from omnipresent ads for junk food to grocery stores with no fresh produce, were nudging them in the opposite direction.

So when a student asked Spoer to "guess what I had for breakfast,” it often was for the pleasure of telling the health guy that she'd eaten three Pop Tarts with a milkshake.

He wasn't exactly surprised. In the kids who were eager to tune him out, he saw himself, not many years earlier. These days Spoer is six-foot-five, lean and broad-shouldered, with red hair and a lively curiosity about the world. But 10 years ago he was a pudgy middle-schooler with few friends, cadging money for extra candy and hiding the peanut-butter-cup wrappers from his parents.

"I was engaged in 'eating my feelings,' " he says.” “Most of the people I dealt with were sure they were happy and yet couldn't figure out why they felt so bad."

After his mother found a pile of candy wrappers in the couch, she availed herself of the kind of resources one doesn’t find around Lincoln High School: she found Spoer a personal trainer, who hooked him on fitness and nutrition. That transformed the chocolate-smuggling C student into a triathlete, marathoner, and rower who routinely earned A's on his report card. "Exercise is what gave me my life," he says.

He graduated from UC Berkeley in 2007 with a degree in philosophy, plans for law school, and a career ambition to become an advocate for children and teens. So Spoer eagerly signed on for a two-year stint working for HealthCorps, a "Peace Corps for health" started in 2003 by the cardiac surgeon Mehmet Oz. HealthCorps recruits — 15,000 so far — are new college graduates who work, for long hours and minimal pay, to help students in underserved high schools assume greater responsibility for their personal health. An independent study recently found that students exposed to Health Corps cut down their soda intake and scored about 10 percent better than average on a test of health knowledge. Most significantly, students were 36 percent more likely to say they had recently become more physically active.

Spoer first walked into his basement office at Lincoln in September 2007; he was almost 22, close enough to the students' age to remember how they see the world (which is part of the HealthCorps strategy). The students’ desire to compete and assert themselves against authority, Spoer realized, could as easily work for him as against. "High schoolers have so much to prove," he says. "Playing off that was probably my best motivational tool."

His first move was to set up a booth in the cafeteria. Then he announced that if anyone could ask him a health question he couldn’t answer, he’d give them a free t-shirt. “I was thronged with kids, 16 to 20 deep, yelling health questions at me,” he recalls. Students were impressed that he knew his stuff (he gave away just three shirts), and even more so that he'd field any question, from "What is diverticulitis?" (a swelling in the wall of the intestine) to "Why is my friend's penis so small?" (Answer: "Probably because he's a small person overall.")

Many other "challenges" followed, each one aimed at engaging teenagers without infringing on their sense of autonomy. (On one occasion, he challenged students to eat nothing but whole grains for a day.) His manner announced to students that he wasn't trying to boss or manipulate them; he worked for them, not the other way around.

"These kids' lives are really hard," Spoer says. "Sometimes the only thing that makes everything okay is a milkshake. If that's what makes your life livable, don't let some dude at school get in your way. But I want you to understand what you're doing to yourself. Understand the consequences."

Spoer also knew he couldn't change teenagers without engaging parents, teachers, and the school itself. He set up a referral system for the guidance department; students who were having chronic problems could be sent to meet with him during the day. To show students the link between nutrition and performance, he kept his office supplied with bread, jelly, and peanut butter. "Peanut butter has good fat and it has protein. Couple that with carbohydrates and a glass of water, you actually have all four macronutrients that you need to have a satisfying meal." Also, he notes, "It's pretty easy to get people's attention when you're handing out free food."

Teachers, eager to see the students improve their performance in class, were happy to become involved. Some even offered an extra five points on a test score to each student who’d eaten breakfast every day that week. Parents, though, were a harder sell, often for reasons that underscore why obesity can plague poorer neighborhoods. Some complained, rightly, that fresh vegetables were hard to find in their local stores. Spoer encouraged them to visit a farmer's market a few subway stops away in a much more prosperous neighborhood, but many teens and parents didn't feel at ease there.

 One of Spoer’s most ambitious challenges asked students to pledge to eat only nutritionally sound foods for an entire two weeks. Those who signed up had to keep a food log and attend two or three meetings a week. Each also was given a button to wear, “so other kids can see you're part of the challenge and bond over it," Spoer says. More than 50 students signed up, and about 30 stuck with the program to the end. "Every single one said they had more energy. A couple had really good improvements in grades. The athletes all performed better on the field. They were freaking out."

HealthCorps, which was designed to find and test ideas, has spread some of Spoer's: His "challenge" approach has been used by volunteers in other schools, as has the "stump the health guy" booth. Meanwhile, the organization changed him as well. Having finished his two-year stint with the program, he now works with it on a new project, "HealthRaisers," a network of athletes who raise money for healthy-lifestyle programs and promote fitness in their communities. He dropped plans for law school and now is preparing to apply to graduate school in health psychology. The mysteries and subtleties of motivation fascinate him, and he often steers the conversation back around to the subject.

"I would say, 'There are no prizes for successfully completing the challenge. Nobody wins it. Your body will give you back prizes that are so much better than anything I can give you.’" Of course, he says, "Half the kids wanted to complete the challenge just so they could tell me they didn't feel any better. If you want to improve your life to spite me, go for it."

David Berreby blogs about behavior at Bigthink.com and has written about science for The New Yorker, The New York Times Magazine, and many other publications. He is the author of Us and Them: The Science of Identity, published by Little, Brown.