When you were young, “pinky swearing” to keep your best friend’s secrets probably felt like a pretty big deal. But these days, kids are getting a lot more serious about their promises: Ask 12-year-old Koa Halpern, the founder of Fast Food Free —a youth-run start-up company aimed at getting kids (and their parents) to commit to healthier lifestyles. Want to take the pledge? It starts with two weeks sans fast food; then you’ll take everyday steps to help save the environment and your health, such as cutting back on or cutting out meat; eating more veggies, grains, and organic foods; and educating the community on healthy eating. Join the cool kids at fastfoodfree.org.