>"It’s easy to attribute omnipotence to one’s devices. I’d hate to know what my iPhone knows about me. That said, there are still aspects of existence that Silicon Valley has yet to quantify (though not, I’m sure, for lack of trying). Calorie-burn might be one of these. While countless apps/devices profess to track it with rigor, it’s not at all clear how accurate their efforts actually are. For this week’s Giz Asks, we sought clarity on this issue with a number of relevant experts."