By Padma Nagappan

Children are generally active when they are young but their level of activity often tapers off as they enter their teens, which leads to a high incidence of obesity, associate professor of preventive medicine at the University of Southern California's Keck School of Medicine Donna Spruijt-Metz said during her remarks at the WLSA's Wireless Health 2012 event last week. The number of obese youths has tripled over the past 30 years, she said.

Spruijt-Metz leads a group of research students in the KNOWME Networks project, which is developing wireless body area networks specifically designed for minority youth. The wearable device offers non-intrusive monitoring of metabolic health, vital signs, and physical activity.

"The distribution of obesity is not fair. Hispanic and African youth suffer more so than their peers. The national obesity average is 45 percent but in Southern California where I live it's 60 percent," Spruijt-Metz said.

She also highlighted how obesity impacts not just health but social life, since obese children are teased, taunted and often have poor body images. Overweight children also have a much higher chance of becoming overweight adults.

"Visceral fat makes them more sensitive to diabetes and cardiovascular disease," Spruijit-Metz said. "Physical activity decreases adiposity, while sedentary behavior increases risk for metabolic syndrome and risk of obesity."

KNOWME has developed a suite of Bluetooth enabled sensors that send streaming data to smartphones, which Nokia supplied for the system's trials. The vital sign data and physical activity data is then transmitted to the project's server where it is analyzed and translated in realtime by observers. Observing researchers then send text messages to the youth with the gist of the data. It can also be shared with care givers and organized and time-stamped to give them a realistic look at the youth's vitals and level of activity.

Spruijt-Metz said the study brought in a group of teenagers and asked them how they'd like to wear the sensors and was surprised to hear that rather than a wrist-watch or band, they would prefer to wear a chest band under their clothes. She also cautioned that one thing to keep in mind is to ensure the data being texted to the children is accurate.

"If you are wrong, you are out of there, then they won't pay any more attention to you," she said.

One of the concerns researchers had was whether the youth would actually wear the band and keep it on.

They trained the focus group of 12 Hispanic youth in their homes and asked them to wear it for 2.5 days, through all their sports, other activities and down times. The remote monitoring team then texted any one who had been sedentary for too long or those that needed trouble shooting. At the end of the period, the team also conducted an exit interview.

"Technology is here not to make things easier but more effective," Spruijit-Metz said. "The personal touch is great and if we do the technology right, by the time we get to clinical trial for this, one minder can handle five to ten kids at a session."

The researchers found that the teenagers were willing to wear the monitor and listen to their suggestions. One even texted the team back that it was "like having a doctor in my pocket".