On a brisk Friday morning at St. Martin de Porres School in North Philadelphia, about 100 neatly uniformed middle school students warmed their fingers in anticipation of a Type 2 diabetes screening. After a pin prick to a fingertip, a medical assistant squeezed a drop of blood onto a strip, and in a few seconds, a blood-sugar reading appeared.

"It's scary," said several kids, who looked relieved when the ordeal was done. The good news?  None of the 100 students tested positive for the disease. But as they learned in the rest of the program, the habits they establish now could help determine whether they remain as healthy in the future.

Organized by the Penn Rodebaugh Diabetes Center, the screenings were followed by a healthy snack, then an assembly conducted by Mark Schutta, the medical director of the center, whose goal is to make youngsters aware of  Type 2 diabetes and how to prevent it.

"I wanted to do this because I remembered health assemblies when I was a kid where experts showed us how to brush our teeth. It stayed with me all these years," Schutta said. "This is a great opportunity to reach kids who are susceptible and get them educated on these subjects."

Although Type 2 diabetes was once called adult-onset diabetes because it usually struck after age 45, that no longer holds true. If you were born in the United States in 2000, Schutta said, you have a 33 percent chance of developing diabetes. African Americans are even more vulnerable than whites, and poor people are more at risk than the affluent.

Projections from the American Diabetes Association show that if obesity rates remain stable over the next 40 years, the number of youths with Type 2 diabetes may increase by 49 percent. However, the same research notes that the more action that is taken to prevent and treat childhood obesity, the likelier it is that diabetes will pose less of a threat.

In Philadelphia, more than one-fifth of children and youths age 5 to 18 have a body mass index (BMI) that is greater than or equal to the 95th percentile for their age and gender group, according to the Community Health Assessment performed in 2014 by the Philadelphia Department of Public Health. (Though obesity among adults is defined as a BMI of 30 or above, children are considered obese if their BMI ranks in the top 5 percent of their age and gender group.)

National data show that Philadelphia ranks first among the seven large cities for which teen-obesity prevalence is known.

Especially in children, "Type 2 is completely preventable by eating a good diet," Schutta said. It's good to get kids when they are young and impressionable. They may not have diabetes now, but when they go through college and start working, they'll be less active and start to gain weight, and weight gain and diabetes are certainly linked."

A major culprit, he said, is carbohydrates, especially  in diets where "chips, breads, and pastas are disproportionate to fruits, vegetables, and proteins," he said. "Kids aren't as active when they get older, and that's when Type 2 can set in."

Providing health education in poorer urban neighborhoods such as North Philadelphia can be challenging. Fruits and vegetables are less available than in more affluent areas, and when they can be found, they are often more expensive. Playing outside, which Schutta noted in the assembly was a big part of his childhood, may be unappealing or even dangerous. And as is the case for all kids, video games, computers, and cellphones may mean it's more fun to stay inside.

Penn hopes to expand the screening/assembly program to other inner-city schools.

John Donnelly, the chairman of the board of St. Martin de Porres School, noted that the board and staff of the school have also been talking about asthma, in addition to diabetes.

"We'd love to test kids in all the inner-city schools for these issues," Donnelly said. "Because recognizing them early is the best way to deal with this epidemic."

Many of the children in the room knew someone in their family or neighborhood who had diabetes.

Kalise Mack, 13, said that her mother's best friend's daughter has high blood sugar, and Kaiya Boyer, 14, reported that her grandmother had diabetes. But when asked whether she were willing to give up her chips, Kalise smiled shyly.

"My chips are kind of mandatory with a sandwich," she admitted.

But those chips are not going to appear at lunch during school hours at St. Martin de Porres, where most children receive a free healthy and balanced breakfast, lunch, and snack during the day.

"We've been trying to raise the issues of healthy eating at school," said Sister Nancy Fitzgerald, the school's principal. "Students can't bring chips, candy, gum, or soda to school, but they can drink water, or eat fruit or fruit roll-ups."

"It's a battle for young people," Fitzgerald said. "This is our first time venturing into health area," she said of the Penn program, "but it's a vital part of teaching them about a healthy future. It's our duty to provide services for our students because health services are not always available to them."