The fight against fat is going high-tech. To get an inside look at eating and exercise habits, scientists are developing wearable wireless sensors to monitor overweight and obese people as they go about their daily lives. The experimental devices are designed to keep track of how many minutes they work out, how much food they consume and even whether they are at a fast-food joint when they should be in the park. The goal is to cut down on self-reported answers that often cover up what's really happening. In a lab in a Los Angeles suburb, two overweight teenagers help test the devices by taking turns sitting, standing, lying down, running on a treadmill and playing Wii. As music thumps in the background, wireless sensors on their chests record their heart rates, stress levels and amount of physical activity. The information is sent to a cell phone. “I can't feel my legs,” 15-year-old Amorette Castillo groans after her second treadmill run. Traditional weight-loss interventions rely mainly on people's memory of what they ate for dinner and how many minutes they worked out. But researchers have long known that method can be unreliable since people often forget details or lie. The new devices are being designed in labs or created with off-the-shelf parts. Some similar instruments are already on the market, including a model that tracks calories burned by measuring motion, sweat and heat with armbands. But the devices in development aim to be more sophisticated by featuring more precise electronics and sometimes even video cameras. Many emerging systems also strive to provide instant feedback and personalized treatment for wearers. At the University of Southern California lab, the teens alternated between being sedentary and active as researchers resolved the technical bugs. Later this year, some will wear the body sensors at home on weekends. If they get too lazy, they will get pinged with a text message. “We'll be able to know real-time if they're inactive, if they're active,” said Donna Spruijt-Metz, a USC child obesity expert in charge of the project. The devices are made possible by advances in technology such as accelerometers that can measure the duration and intensity of a workout. They also use Bluetooth-enabled cell phones that can take pictures of meals and send information back. Will all this wizardry lead to a slimmer society? Scientists say there's reason to hope. Getting an accurate picture of what people eat and how often they move around will help researchers develop personalized weight-loss advice. By using technology to capture eating and exercise details, researchers hope to bypass self-reporting that can sometimes give an incomplete picture. But some medical experts are concerned about ethical questions. Even if people agree to be tracked, researchers worry about intruding into the rest of their lives and the lives of those around them. Another concern is whether people, particularly youngsters, will stick with it. Fellow Pittsburgh researcher Dana Rofey recently completed a study of 20 overweight female preteens and teens who wore armbands tracking the number of steps taken and calories burned daily. Researchers found the armbands were worn 75 percent of the time.
