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make us come back for more.

       Does this kind of "food" even meet the criteria for what food is supposed to be?

      It used to be that we needed to chew the average bite of food from 20 to 30 times. Today it's a fraction of that. Food goes down in a whoosh. It's almost as though it's predigested. It's like we're eating baby food all the time. We're just constantly stimulating ourselves. We're eating for reward—not for fuel or nutrition.

      What's going on today is that combinations of fat, sugar, and salt stimulate the reward circuits and get us coming back for more. The reward centers of our brain regulate such behaviors as eating, drug use, and sexual reproduction. We can now look into the brain. For people who have a hard time resisting their favorite foods, we see that fat, sugar, and salt stimulate their brains. In fact, these substances highjack the reward pathways. You can actually see this activation in their brains.

       Are children more vulnerable than adults are?

      There's no doubt about that. Let's go through how this works. On the basis of past learning, memories, and experience, you get cued. A cue could be a sight, smell, time of day, or location. For example, I walk down a street that I walked down six months earlier. I've forgotten entirely that on that previous walk, I went into a store that sold chocolate-covered pretzels. Now that I'm back on that street, I start thinking about chocolate-covered pretzels. That's a cue.

      You associate these cues with the actual food itself. That cue focuses your attention. It stimulates thoughts of wanting. You get this momentary pleasure from responding to the cue—by eating the chocolate-covered pretzels. The next time you get cued, you do it again and repeat the cycle. The behavior becomes both conditioned (learned) and motivated (driven). Once you lay down those learning circuits and those motivational circuits—certainly if you do it in childhood as it's happening today—they stay with you for a lifetime.

      Kids are the most vulnerable. When I was growing up, I wasn't being constantly bombarded by food. It wasn't available on every corner, in every gas station, during most of our waking hours. Now our kids are growing up, not just with food that's been highly developed to be stimulating—layered and loaded with fat, sugar, and salt, which stimulates intake—but they're also constantly bombarded with food cues.

      Food has to be rewarding. It has to be pleasurable. But I certainly want food that's going to nourish me, that will make me feel full and give me fuel. I don't want food that's going to keep me coming back for more.

      My colleague, Dr. Gaetano Di Chiara, one of the great pharmacologists, studies the effect of cocaine and amphetamine on the brain. He finds that cocaine and amphetamine elevate the brain's dopamine circuitry. Dopamine is the chemical that locks in your attention, that gets you focused on the drugs and drives wanting.

      We always thought that food gave you a little bump in dopamine the first time, but the second and third times it did not. So I said to Gaetano, let's not use just one ingredient, let's make the food highly palatable; let's take fat and sugar, put them together, and see whether we can get rises in brain dopamine. And we got exactly that—not only the first time, but repeatedly.

       What are the repercussions for childhood obesity in the United States?

      Let me give you an example. An average 2-year-old knows how to compensate for his or her eating. If the child eats more calories at lunch, he or she will typically eat fewer calories later on in the day. But by 4 or 5 years old, children lose the ability to compensate because they've been exposed to diets that are high in fat, sugar, and salt. They're now eating for reward—and not for fuel.

      The greatest gift you can give someone is to lay down healthy eating patterns from the beginning, to find foods that are rewarding as well as healthy. If you continually expose children to fat, sugar, and salt, they will find these foods to be their friends. They will use them to feel good. If that's the case, it's hard to break the habit. Yes, you can retrain the brain, but you do it by laying down new neural circuitry, new learning on top of old.

       How can schools help with laying down this new learning?

      Once we understand that the constant availability of fat, sugar, and salt conditions and drives our behavior as well as the behavior of our kids, it has profound implications—for school lunch programs, for vending machines, for when we eat, for how we use food, and for how we educate. The best thing that schools can do is to teach kids about nutrition and help them understand that fat, sugar, and salt—although they taste good for the moment—will only stimulate them to come back for more. That if they use food as a reward or for purposes other than for nutrition and fuel, they're contributing to laying down that neural circuitry. That if they use food to regulate mood, then they're going to be stuck in that cycle for the rest of their lives.

      Kids look at that huge plate of food now and say, "That's what I want." That's a hard cycle to break. And it's having a profound effect on their health. In the past, adults would get type 2 diabetes in their 40s or 50s, then live for two or three decades with the disease, developing eye disease, kidney disease, cardiovascular disease, and other complications. But kids are now getting type 2 diabetes—at 10 years old! What's going to be the effect of living, not for two or three decades with the disease, but for four, five, and six decades? That concerns me as a pediatrician.

      Limiting where we eat, when we eat, and what we eat is vitally important with kids. But we can't just deprive our kids or give them rules. If kids feel deprived, it's not going to work. You've got to give them the tools so they can understand what good nutrition is so they will want to eat foods that will sustain, satisfy, and nourish them.

      There are going to be problems if our kids eat foods layered with fat, sugar, and salt for lunch at school, if they use vending machines there, and if stores around the school also sell products layered with fat, sugar, and salt.

      We all got into this jam together. We created this problem in the last four or five decades—and it's going to take all of us to undo it. You can't just do it at home, you can't just do it in the schools—you have to do it together.

      Originally published in the December 2009/January 2010 issue of Educational Leadership, 67(4), pp. 6–10.

      A Supersize Problem

      by Eric K. Gill

       School wellness policies tackle overweight students, declining physical activities, and everpopular vending machines.

      An estimated 17 percent of U.S. children are overweight, and policymakers are turning to schools to help students trim down and shape up. The Centers for Disease Control (CDC) and Prevention reports the number of overweight children ages 6–11 has doubled in the past 20 years; for adolescents 12–19 years old, the overweight figure has tripled. The CDC found that 80 percent of all high school students fail to eat the recommended daily allowance of fruits and vegetables, while more than 60 percent of U.S. children consume too much saturated fat (U.S. Department of Health and Human Services, 2006).

      These statistics arrive 40 years after President Lyndon B. Johnson signed the Child Nutrition Act. At the time, many children in poor urban and rural communities came to school hungry and went home unfed. The law acknowledged the relationship between "nutrition and the capacity of children to develop and learn," and the government pledged to assist states "through grants-in-aid and other means, to meet more effectively the nutritional needs of our children" (Child Nutrition Act of 1966, Section 2).

      Today's overweight epidemic is also occurring predominantly within the nation's poorest urban and rural areas. The CDC reports childhood overweight numbers are highest among Mexican American boys, non-Hispanic black girls, American Indian youth, and non-Hispanic white students from low-income families. In its well-meaning effort to feed the nation's poorest children, it seems the United States has succeeded at feeding them poorly.

      Generation Extra Large

      Among the many causes of today's overweight problem are fast-food chains, snack-food companies, and beverage manufacturers,

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