CHICAGO — Paz Soto didn't even consider her son overweight, so the doctor's next piece of news shocked her. Andy had developed fatty liver disease, a potentially life-threatening chronic condition usually found in middle-aged adults.

"I was really scared when I heard that something was wrong with his liver," she said through a Spanish interpreter. "The doctor said Andy's liver got fatty like someone who drinks a lot."

Andy was just 8 years old at the time.

With an epidemic of obesity affecting American children and adolescents, doctors say a growing number are being diagnosed with chronic diseases once considered illnesses of adulthood.

In addition to the well-known rise in type 2 diabetes among U.S. youth, overweight children also are suffering from fatty liver disease, hypertension, high cholesterol and sleep apnea. Health professionals are increasingly concerned, fearing the long-term impact of developing chronic diseases early in life.

"The earlier you develop diabetes, the more likely you are to develop complications," said Dr. Paula Butler, chief of endocrinology at Mt. Sinai Hospital. "People will be having eye problems early, heart problems early, strokes early and go on dialysis. They will suffer knee and back pain, have sleep problems. They may not be able to work. It affects quality of life."

Of 14 pediatric patients Butler saw on a recent morning, two had borderline diabetes and changes in liver function because of their weight. "Over the last 10 years, people have started to recognize this increasing obesity and all the things that go along with it," Butler said.

As a result, many pediatricians are learning how to take care of health problems they didn't have to treat before, said Dr. Surendra Varma, chairman of the endocrinology section of the American Academy of Pediatrics.

"There is an epidemic of type 2 diabetes," he said. "We are encountering lipid disorders, sleep apnea and hypertension with good frequency in our practices."

The trend can be seen in the rising number of prescriptions for medications that treat the conditions. Two national pharmacy benefits companies recently reported staggering rises in prescriptions of type 2 diabetes drugs for children and teenagers.

One of them, Medco Health Solutions Inc., found use of diabetes drugs rose 167 percent for girls ages 10 to 19 between 2001 and 2006. For boys the same ages, it rose 91 percent.

The companies' research also showed smaller increases in use of medications for other chronic illnesses, including drugs to fight high blood pressure and lipid-lowering medications.

Varma said poor diet and lack of exercise are largely to blame for the problem.

"The inheritance of these adult diseases in childhood is a result of our consuming too much fast food and not requiring significant physical activity on a daily basis," Varma said.

Soto said she didn't even realize her son was overweight until his pediatrician showed her his growth charts during an annual physical. She was stunned to learn that Andy was heavier than more than 97 percent of the children his age, or about 33 pounds over his ideal body weight.

At 8, he weighed as much as boys of average weight almost six years older.

Andy also had fatty liver disease, a condition in which the body stores excess fat in the liver. It typically is found in adults who indulge in high-fat foods or regularly drink large amounts of alcohol. The disease can permanently damage the liver.

Children with fatty liver disease tend to be overweight, Butler said.

"There's probably a genetic propensity for diabetes that plays into it too," she said. Andy Soto has a family history of diabetes on his father's side.

The Sotos now participate in a healthy diet and fitness program at Sinai Children's Hospital called Sinai Fit. In the past, Andy's foods of choice included pizza and hamburgers or virtually anything made of beef and pork, but his mother has cut down on her meat purchases and avoids cooking with lard, a practice she learned in her native Mexico.

Andy, now 11, and other family members are learning how to make healthier food choices and to exercise regularly. But making lifestyle changes isn't easy, even when the stakes are high.

"It's sometimes very hard to get people to give up what they are used to eating," Butler said. "Some of it is economic. Parents work. It's easier to stop at McDonald's or Kentucky Fried Chicken and pick up something to take home than to cook."

For that reason, some health professionals are taking more drastic measures to help children lose weight. Dr. Brian Edelstein, co-director of the Nutritional Wellness Center at Sinai Children's Hospital, prescribes appetite suppressants for children who fail to lose sufficient weight on their own.

"They've tried conservative management and interventions with calorie counting and exercise and it doesn't seem to be working," Edelstein said. "Do you let them spiral toward a condition that clearly has a decreased life span and clearly is associated with things like dementia, liver cancer, early heart disease and stroke?"

Dr. Cynthia Mears, a specialist in adolescent medicine at Children's Memorial Hospital, said the problems can be compounded as the children enter adolescence. Overweight children often reach puberty earlier, she said, and hormonal changes can make losing weight even more difficult.

FAST FOOD 'A WAY OF LIFE'

Shortly after her children moved back to the United States from Mexico in 2005, Saskia Rios noticed they were packing on the pounds.

Her son Fernando Valladolid, who at 12 years old weighs almost 300 pounds, has struggled most. Rios is also mother to Fernando's fraternal twin, Victor; Andrea Valladolid, 8, and Edgar Tellez, 9 months.

Fernando has been diagnosed with acanthosis nigricans, a darkening of the skin that appears most prominently around the neck, armpits and elbows. The skin changes are a sign of metabolic syndrome, a constellation of conditions that puts a person at risk for diabetes, heart disease and stroke.

For Rios, monitoring her children's eating is difficult, as she commutes two hours each way to a full-time office job in Elk Grove Village and tends bar part time on the weekends. Her husband works a full-time job with long hours.

But she is trying. At the suggestion of Sinai Fit, she bought size-appropriate plates and cups to help the children judge portion sizes when adults are not there to supervise.

On a recent trip to a produce market at Cermak Road and Cicero Avenue, the children practiced their recently acquired healthy-living skills by reading food labels, making sure the wheat bread they were buying was whole grain.

"I feel like I've been a bad mother," Rios said apologetically. "I've said: 'I'm not going to McDonald's anymore.' But when you're out and you're running late and the kids are hungry, you find yourself rolling through McDonald's. It's the way of life here."