Red, yellow, green. It's a system for conveying the healthfulness of foods, and at the center of a debate about how to approach weight loss for children.
This month, the company formerly known as Weight Watchers provoked a backlash when it introduced a food tracking app for children as young as 8. The app uses a well-known traffic-light system to classify foods, giving children a weekly limit of 42 "reds," which include steak, peanut butter and chips.