Orlando, Fla. ? A growing number of young teenagers are overweight and at risk of developing diabetes, and families are often blind to their children’s obesity and its dangers, according to two studies released Friday.

The findings underscore an alarm that doctors have been sounding: Diabetes, one of the severe consequences of obesity, is growing at a troubling rate while many people at risk do little to prevent it.

The research was presented at the annual meeting of the American Diabetes Assn., which runs through Tuesday in Orlando.

One study found that more than half of eighth-graders have at least one contributing factor for developing diabetes.

“We’re looking at eighth-grade students in three states, and across the board, they are at risk for (eventually developing) diabetes and cardiovascular disease,” said Dr. Francine Kaufman from Children’s Hospital of Los Angeles.

The condition has become a top concern, afflicting more than 18 million Americans, including about 200,000 who are younger than 20. Most have a form called type 2 diabetes, which used to strike older people after many years of poor eating and lack of exercise.

But as the number of overweight children has grown, doctors have noted an alarming rise of type 2 diabetes in young people. Diabetes, which hampers how the body processes sugar, can lead to blindness, amputations, heart disease, stroke and other complications.

In the study of American eighth-graders, researchers found that more than half of the 1,740 kids studied in Texas, North Carolina and California had at least one serious risk factor for diabetes.

The dangers aren’t being recognized by many families, according to a separate study conducted in the United Kingdom that found 62 percent of obese children don’t see themselves as overweight. The 300 kids, all age 7, were asked to pick a silhouette that best described their bodies — anything from very slim to obese.

“Some of the obese children chose silhouettes that were quite thin,” said Alison Jeffery, a senior researcher in the study. “It’s as if our perceptions have somehow shifted.”

What’s more, nearly 75 percent of parents with overweight children underestimated their children’s weights.