Q. Is it true that my overweight teen is at risk for liver disease?

A. Physicians in children's hospitals are seeing liver disease in more kids and teens than ever before. In a few cases, it is severe enough to require a liver transplant. One of the main causes appears to be too much body fat.

The type of liver disease seen most often in kids is called "non-alcoholic fatty liver." The American Liver Foundation estimates that 2 percent to 5 percent of American children have the condition. Nearly all of them are obese or overweight. There may be even more children with the condition, but it is hard to know since few are tested for it.

The disease begins with excess fat building up in the liver cells. This can cause the liver to become inflamed. Over time, scar tissue can form in the liver and cause a more severe condition called cirrhosis. Cirrhosis is very serious and can lead to liver failure. This is similar to what happens to the livers of some alcoholics and people with hepatitis.

Fatty liver also increases a child's risk for heart disease. If scarring hasn't yet developed, fatty liver can be reversed with weight loss.

What's scary about this disease is that it is silent. Fat can build up for years in the liver without causing any symptoms. Fatigue, stomach pain and unexplained weight loss may be present. However, they usually appear only when the disease is in its advanced stages.

Some liver specialists predict that many more of today's obese children will develop severe liver disease in their 30s and 40s, requiring a liver transplant. This will be a result of developing undiagnosed fatty liver as a child.

Fatty liver is most common in overweight children with belly fat who may also have diabetes, high blood pressure or elevated cholesterol. The American Academy of Pediatrics now recommends pediatricians do a blood test of liver enzymes every two years on obese children.

The group also recommends this test for overweight children with high blood pressure, high cholesterol or a family history of heart disease. Those with type 2 diabetes or pre-diabetes should also be tested.

The best way to combat the problem is to intervene early, while it can be reversed. Researchers are testing the diabetes medication Metformin and vitamin E as possible treatments. For now, healthy eating and exercise are your best defense.

Amy Tousman is a registered dietitian and certified diabetes educator with Nutrition Unlimited in Kailua. Hawai'i experts in traditional medicine, naturopathic medicine and diet take turns writing the Prescriptions column. Send your questions to: Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Hono-lulu, HI 96802; fax 535-8170; e-mail islandlife@honoluluadvertiser.com. This column is not intended to provide medical advice.