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The war against childhood obesity

David Ludwig, MD

Fifteen-year-old Nick sits uncomfortably in David Ludwig's examining room. He grins and throws his sweatshirt over his head in embarrassment as his father, Gary, does most of the talking.

"The doctors kept saying he'll grow out of it," Gary tells Ludwig. "But he grew into it. He eats what he wants, whenever. At 2, 3, 4, 5 a.m."

Ludwig, who is the director of Children's Hospital Boston's Optimal Weight for Life (OWL) program, runs through a barrage of medical questions: How's your energy and strength? Any changes in skin and hair? Do you have excessive thirst or excessive urination? Shortness of breath?

Nick says no to these, but yes, he has asthma, high blood pressure and constant heartburn—a burning in his throat a few hours after eating, especially at night.

"That's why he sleeps sitting up," his sister, Jessica, a certified nurse's aide, adds.
"That could be a serious medical problem," Ludwig says. Nick also has sleep apnea—loud snoring. Does he stop breathing? The family thinks possibly he does.

"Listen carefully for that," Ludwig warns them. "If you hear him gasping for air, that's another serious medical problem, one that could be life-threatening."
Physical activity? "We try to get out on the basketball court," Gary says. But on most days, Nick is inactive.

Now come the dietary questions.

"What's the first thing you have to eat every day?" Ludwig asks. At 9 a.m., Nick has a bag of chips from the vending machine at school; for lunch, he has a Gatorade from the machine. In fact, Nick's first real meal isn't until 2:30 p.m. when he arrives home from school and eats leftovers from the lunch Gary has prepared. Sometimes, if there's enough food, he'll have a second meal.

"What happens at night?" The family pauses. "I've seen it all," Ludwig says. "Nothing you say can shock me."

Gradually, it emerges that Nick binges at night, eating hot dogs 10 at a time, a pound of cheese, chips, candy.

Ludwig does a physical exam. "I want to show you something," he tells the family. "Do you see this discolored skin here?" He points out a patch of dark, velvety skin in the fold of Nick's neck.

"He doesn't keep it clean," Gary says in exasperation. "We've been after him to clean it."

"It doesn't come off," says Donna, Nick's mother. "I've tried scrubbing it."

"This is a skin condition called acanthosis nigricans," Ludwig says. "It goes along with being obese."

He explains that it signals high levels of insulin in the body—an indication that Nick, at over 300 pounds, is at risk for diabetes. "Luckily, it's just a warning sign," Ludwig tells the family. "It's saying, ‘Keep an eye on the road and drive carefully.'"

The road to Washington
Ludwig began his career in the laboratory, studying the molecular basis of obesity. He is credited with helping to find a gene in the brain that makes a compound that stimulates hunger, called MCH (melanin concentrated hormone). In the 1990s, Ludwig demonstrated that mice bred to make extra amounts of MCH had a greater tendency to become obese. But he decided that wasn't enough.

"There are hundreds of genetic factors in obesity, and I came to feel that identifying yet another gene wasn't going to end the obesity epidemic," he says. "Our genes haven't changed in the last 30 years—while obesity rates have tripled."

Nick binges at night, eating hot dogs 10 at a time, a pound of cheese, chips, candy.
Instead, Ludwig believed that it was environmental factors—social and cultural—that needed to be changed. This view led him back to clinical work and eventually transformed him into what Time magazine has termed an "Obesity Warrior." He has testified in Washington, D.C., and speaks publicly and often about the need for government measures—including restrictions on food industry and advertising practices—to curb the obesity epidemic.

"Childhood obesity really winds up being a political issue," Ludwig says. "I came from a very politically active family, and some of my earliest memories are of being taken to civil rights demonstrations and anti-Vietnam war protests. I've kind of returned to my roots."

Ludwig founded the OWL program in 1996, and today it is the largest pediatric obesity program in New England, caring for more than 500 obese children and adolescents each year. Services include medical examinations, comprehensive nutritional counseling, exercise training, behavior modification and group therapy.

But Ludwig believes that much of the responsibility for obesity falls on society, and he doesn't mind stepping on toes in saying so. He's irked by the suggestion that curbing obesity is a matter of self-control and personal responsibility.

"This argument is used as a smokescreen to maintain the status quo," Ludwig contends. "Blaming the mother for her child's obesity takes the onus off the food industry for advertising junk food to young children, and politicians for not taking actions against these practices. In any other epidemic, we would seek to maximize both personal and societal responsibility. No public health expert would try to solve the AIDS epidemic just by telling people to act responsibly."

A toxic environment
Ludwig feels parents want to do the right thing, but that their efforts are drowned out by a food environment that's "overwhelmingly toxic." "If we were to reverse environmental factors back to those of the 1960s, virtually the entire obesity epidemic would disappear," he asserts.

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Changes in the past 40 years have been enormous. Fast food, junk food, and soft drinks have become a prominent part of the landscape, and food advertising directed at children has exploded. "Just watch Saturday morning television," Ludwig says. "The food industry pays billions of dollars to convince young children to eat the most unhealthful foods imaginable. What's being marketed to kids is a nutritonal nuclear bomb—no fiber, no fruits, no vegetables, no vitamins, no minerals."

And portion sizes have ballooned. Today, a single "supersize" fast food meal can contain a child's total daily calorie requirements, Ludwig says. "And it's consumable in 15 minutes, before the body recognizes that the calories have come in, before the child feels full."

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Social changes are as much to blame for the obesity epidemic. To help fund their programs, schools have become purveyors of fast food and soft drinks through contracts with the food and beverage industry—even as they cut physical education classes from their curricula to save money.

Lured by TV and computers, and because of parents' safety concerns, kids are spending less and less time outside burning off calories. Cities and suburbs increasingly lack parks and sidewalks. And increased stress on families leaves parents less time to supervise their children's diet and exercise habits—"leaving children increasingly vulnerable to the marketing and advertising tactics of the food industry," Ludwig says.

Low-fat diets: part of the solution or part of the problem?
The solution society came up with to the obesity problem was low-fat diets, but Ludwig believes they have actually made matters worse.

"It would seem to make sense that if you don't want fat on your body, you shouldn't put fat in your body," he says. "Unfortunately, that message is much too simplistic. By reducing fat and replacing it with carbohydrates, we may have done more harm than good in terms of hunger and ability to regulate body weight."

Just as there are good fats and bad fats, there are good and bad carbohydrates. What's increased dramatically in the American diet are the "bad" carbs—foods like white bread, refined breakfast cereals and concentrated sugars—that are rapidly digested and raise blood glucose and insulin to high levels, changes that eventually can lead to diabetes. Such foods are said to have a high glycemic index, or GI. "Good" carbohydrates—foods like whole grains, most fruits, vegetables, nuts and legumes—have a low GI, meaning they're low in sugar or release sugar slowly.

The first study Ludwig did outside his basic-science lab found that a high-GI meal can actually make kids more hungry and cause them to overeat. It seemed like a strange notion, and Ludwig had no experience doing diet studies, but he convinced Children's to give him a $20,000 pilot grant. With the money, Ludwig's team recruited 12 obese teenage boys, admitted them to the hospital overnight, fed them low-GI dinners, and provided them with different test meals to eat for breakfast and lunch the following day. The test meals were formulated to have low, medium, or high GIs. During the five hours after lunch, the boys could request and eat as much as they liked whenever they felt hungry.

When food intakes were compared, the total energy intake after the high-GI lunch was 53 percent greater than after the medium-GI lunch, and 81 percent greater than after the low-GI lunch. Compared with the low-GI meal, the high-GI meal raised insulin levels. Basically, when the boys ate high glycemic foods, their blood sugar went up and crashed a few hours later, fueling hunger.

The study, published in the journal Pediatrics in January 1999, received a flood of publicity, and became Ludwig's calling card to get more research funding. His subsequent studies have shown that reduced-GI diets may produce more weight loss in obese adolescents than conventional reduced-fat diets; that each additional serving of a sugar-sweetened beverage increases a child's risk for obesity by 60 percent; that 30 percent of American children eat fast food on a given day; and that children consume substantially more total calories, with poorer nutritional quality, on days when they eat fast food.

Ludwig theorizes that glycemic index and related dietary factors can even affect a child's risk for attention deficit hyperactivity disorder (ADHD). "When blood sugar crashes, adrenaline skyrockets," Ludwig says. (Some theorize that adrenaline has a role in regulating attention and impulse control.) "Isn't it interesting that the prevalence of ADHD has skyrocketed along with the glycemic index of our diets and childhood obesity?" Ludwig's group conducted a pilot study on diet and ADHD, and is considering a larger study in the future.

The Atkins alternative
In August 2004, Ludwig published a study in The Lancet that provides the clearest evidence yet that a low-GI diet can lead to weight loss, reduced body fat, and reduced risk factors for diabetes and cardiovascular disease. Previous studies have also found benefits of low-GI diets, but these benefits could have been due to other dietary factors like fiber intake. This study eliminated that problem, feeding rats and mice tightly controlled diets that were identical except for the type of starch: one group ate a high-GI starch and the other a low-GI starch.

At follow-up, rats eating the high-GI starch had 71 percent more body fat than the low-GI group. They also had significantly greater increases in blood glucose and insulin levels on an oral glucose tolerance test, and far more abnormalities in the pancreatic islet cells that make insulin, all changes that occur in diabetes. Finally, their blood levels of triglycerides—fatty acids that, when elevated, have been linked to atherosclerosis and heart disease—nearly tripled compared with the low-GI group. Rats that were switched from a low- to high-GI diet showed greater increases in blood glucose and insulin than rats that were switched from high- to low-GI diets.

Additional studies in mice bore out these results: mice assigned to a high-GI diet had 93 percent more body fat than mice on a low-GI diet.

"This is the first study that shows that glycemic index, as an independent factor, can have dramatic effects on obesity, diabetes and heart disease," says Ludwig.

Ludwig hopes that his findings will prompt major health agencies and professional associations to reference glycemic index in their dietary guidelines. He sees the low-GI diet as a more viable alternative to low-carb diets like the popular Atkins diet.

While Atkins dieters seek to minimize carbohydrate intake, the low-GI diet makes distinctions among carbs. "The Atkins diet tries to get rid of all carbohydrates, which we think is excessively restrictive," says Ludwig. "You don't have to go to this extreme if you pay attention to the glycemic index and choose low-GI carbs."

Show me the money
Ludwig's OWL program struggles to stay afloat financially. It receives no government support and "very marginal insurance reimbursement," Ludwig says. "Many insurance companies will not reimburse at all, or limit reimbursement to three visits." As a result, OWL's staff members spend a great deal of time writing letters of appeal to insurance companies when they would rather be treating patients.

"Can you imagine an insurance company saying to the parents of a child with leukemia, ‘Your child has a particularly high-risk version that hasn't been cured in three visits, so we're going to cut off coverage now'?" Ludwig asked U.S. senators at a Congressional hearing in June. "That's a routine statement to parents of children with obesity."

 

An obesity index


With "adult" diabetes and atherosclerosis sharply rising in children and adolescents, obesity treatment and prevention would seem to be a smart investment. Yet nationally, there is as little as 10 percent average reimbursement for obesity treatment, Ludwig says. "Why would we want to pay $60,000 or more for coronary bypass surgery, but not a few hundred dollars for measures that would prevent the need for it in the first place?" he asks.

Nick's parents have struggled to get his weight-loss visits covered by insurance. Gary has been laid off, and this year, the family was forced to move from their 13-room house to a two-bedroom apartment. Financial concerns have clearly put stress on the family, and during Nick's visit, Ludwig offers the family a consultation with a behavioral therapist to address possible psychological issues behind Nick's binge eating.

"Sometimes when people are feeling sad or depressed or angry, they deal with that by eating a tremendous amount of food," he explains.

A therapist is available that morning, but Gary is concerned the session won't be covered by the family's insurance, so it's put on the back burner.

Preventing obesity
Dimitri Athanasiadis is also 15, an affable, outgoing kid whose parents own a pizzeria. Dimitri works there Friday nights and all day Sunday, but in the summer he worked full time, waiting on customers, working the register, answering the phone and helping prepare food.

"I would say the summer was a test of my willpower," he says. "You have everything here for you—fried chicken, steak and cheese, pizza, wraps. It's like a multiple choice test—which are you going to pick?"

Dimitri is in Children's One Step Ahead program. Developed by the Children's Hospital Primary Care Center, One Step Ahead directs children toward nutritional plans and physical activity opportunities both at home and in the community. While the OWL program is for people who are already obese, One Step Ahead is designed to prevent overweight children from progressing to obesity.

Dimitri, about 200 pounds and almost 5 feet 6 inches tall, receives his primary care at Children's. His pediatrician recommended him for One Step Ahead because he was gaining
weight at each visit. Dimitri sees four people in the program: a doctor, a nutritionist, a social worker and an exercise/physical activity coach.

"They devised a plan for me," Dimitri says. "You have to eat in portions. A good portion is the size of your fist. You can't just load up your plate and sit down. With pasta especially, I used to load up my plate. Sometimes I would even have seconds."

"Sometimes even more than you were supposed to eat the first time," adds Georgia, Dimitri's mother.

"Now I try to measure portions with my fist. If it's too much I'll put some back. If we have chicken parmesan, I'll try to find just the right size piece—not too large, but not too small. You want to eat enough to feel satisfied."

Dimitri also avoids juices now, drinking mostly water to cut down on sugar. "You think juices are good, but they're not," he says. "I used to drink an amazing amount of Gatorade, and I've cut down on that too.

"They show you how much sugar is in a Coke—I was just dumbfounded," Dimitri adds. "It's like eating a can of sugar—that is absolutely gross. In the chicken sandwich at Burger King, the mayo alone has the same amount of calories as a medium order of fries. That makes you think twice before you eat it."

In addition to dietary counseling, Dimitri received a device that clips onto his belt and measures how many steps he's taken. The goal is for him to take at least 10,000 steps every day. "You think it's easy, but it's not at all," Dimitri says. "You cannot sit down, you've got to stay moving. You can't watch TV. I create ways to move around, because if you sit down, you're not getting up! You can't be lazy."

In the beginning, Dimitri had appointments every three months, "but I wanted monthly," he says. That way, there would always be a visit coming up pretty soon where he'd be weighed—and that's helped push him to stay with the program.

Like Nick's family, the Athanasiadis family has difficulty affording Dimitri's sessions. As small business owners, the family has no insurance. They receive some assistance from the hospital.

After losing an initial 10 pounds, Dimitri's weight has stabilized, despite him growing in height. His caregivers would now like to see more weight loss. The possibility of weight-loss medication has been mentioned, but neither Dimitri nor his mother believe in pills. "I believe it's 100 percent better to do it naturally," Georgia says. "Because I know he can do it. I don't care if it takes longer, as long as he's taking that road."

Children's Hospital Boston is now recruiting adults to join a large-scale, 18-month study of the low-GI diet. Subjects will receive comprehensive dietary and behavioral counseling in individual and group sessions that will enable them to put low-GI diets into effect. To enroll, subjects must be overweight, 18 to 35 years old, and motivated to attend weekly sessions for four months and return for follow-up through 18 months. People interested in enrolling should contact Erica Garcia-Lago at (617) 355-2500.


To learn more about supporting obesity research and
the Optimal Weight for Life clinic, contact Sara Kelly at the
Children's Hospital Trust, (617) 355-2562 or sara.kelly@chtrust.org.


Dream is published by Children's Hospital Boston. © 2003 Children's Hospital Boston. All rights reserved.