This one should be a no-brainer. You don't want your kids knocking back a cold beer with their after-school snack. Plus, in many U.S. states, you could get arrested for giving underage kids alcohol. Even if you live in a part of the world where it's OK for kids to drink wine or beer with dinner, take note: Each sip can affect their growth and development. According to the American Medical Association, when kids drink alcohol, it affects memory and impairs learning even more than it does in adults. And as kids' developing bodies attempt to metabolize the alcohol and calories at the same time, it can cause them to gain weight in a hurry.