Fight against fat goes high-tech

 
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 this 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 personalised treatment for wearers.