That drove Ms. Stolk to the Internet, where she discovered Wellspring. She signed her daughter up for its California summer camp in 2006, when Carmen was 15 and weighed 270 pounds. She lost 30 at the camp and another 30 when she came home.
"She came back a changed person," Ms. Stolk says.
The students milling about Wellspring's low-slung, 68-acre campus of portables, dormitories and administration buildings look at first like teens at any other high school. They sport tattoos and baggy clothes and saunter slowly between classes.
Here, though, the average student carries 60 to 100 extra pounds, everyone wears a pedometer and no one is glued to a cellphone - they're banned, along with cigarettes and televisions in the dorms. The only two TVs on campus hang on the gym wall, smack in front of the treadmills.
The school offers team sports and recommends long daily walks, but fitness class is mandatory. "For many of these kids, it's their first exposure to exercise," says Jeremy Berumen, the tanned and buff 22-year-old who runs the program. "They run a bit and they can't breathe. ... I start them with basic moves that might be as simple as sitting in a chair and standing up."
About 10 per cent of the students battle diabetes, high cholesterol, hypertension and other weight-related conditions. A third of the students take psychotropic drugs - mostly antidepressants or anti-anxiety medication. All must attend group and individual cognitive-behavioural therapy sessions, underscoring the backbone of the program - self-monitoring.
Somewhere in every student's pocket or backpack is a journal in which they track their physical activities and their daily diets. Mr. Obbard, the headmaster, calls it "think and ink." He says it's the key to teaching "weigh-control skills, versus weight loss."
Boys and girls eat their three meals a day separately, in a windowed, cafeteria-style dining hall in the middle of the campus. They aim for around 1,200 calories a day and less than 20 grams of fat, combining "controlled" hot meals with "uncontrolled" fruit and salad selections along with the riot of condiments on the long cafeteria tables - chilies, malt vinegar, chipotle sauce, Worcestershire, hot sauce, cinnamon, salt and baskets of Splenda, the artificial sweetener 600 times sweeter than sugar.
Here, Splenda is a food group. Students rip open the little yellow packets by the dozen. They drown their cereals in it, shower their fruit with it, cook with it and lick it straight off their fingers. One boy pours more than 20 packs on his yogurt. School chef Erin Gaughan, who teaches students to flavour food without fat, says they "are almost like smokers. ... Their tongues have dried out from all the fat they've eaten."
The school leaves the students free to make their own dietary choices. They can eat white bread, drink unlimited amounts of diet sodas from the dispensers and devour 10 bananas for lunch. They learn at the weekly weigh-in what the consequences have been.
Still, says John Gordon, the school's marketing executive, "no balloons come floating out or anything if you lose a bunch." It's successful self-monitoring and physical activity that earn the coveted privileges of phone time and nights off campus.
But when they do lose, Mr. Craig says, students become less homesick and more motivated to succeed.
They all know success is possible. Some of the biggest losers sit right beside them in class. Chris Grayson, for example, arrived from Connecticut in April, 2007, weighing 325 pounds. He lost 145 of them in 11 months. At 18, he's slim and strong and runs a seven-minute mile.
Terry Henry of New Hampshire was the largest student Wellspring ever had. He weighed 590 pounds when he arrived in 2004 and lost 300 in one year. Terry is long gone (and has managed to keep his weight around 220 pounds) but his old denim shorts and T-shirt still hang in the hallway, stretching across the corridor wall like a victory flag.
After Wellspring camp, Carmen kept the weight off for a year. "But last summer I sat around a lot," she admits. "I was bored and eating ... ice cream, cookies, whatever was around."
Her mother says Carmen has to learn self-control. "If I had something in the house, banana bread, say, she would find it and eat the whole thing. I couldn't keep anything in the house. But how fair is that to the rest of the family?"