A school in Texas is keeping track of what kids eat. “Here's how it works: students are assigned lunch trays with a unique bar code. After the children load up their plates down the line — mashed potatoes or green beans? french fries or fruit? — a camera above the cashier takes a picture of each tray. When lunch is over and the kids return their plates to the kitchen, another camera takes a snapshot of what's left on the tray. Software then analyzes the before and after photos to calculate calories consumed and, according to Trevino, a report of nutrients in the foods.