What makes a renowned heart surgeon like Dr. Oz so passionate about childhood obesity? It's because he personally witnesses what happens when unhealthy 10-year-olds become unhealthy young adults with heart problems. "When you're operating on 25-year-olds … you feel a big obligation to speak up about it," he says. "It brings tears to us because we know it's preventable."

If you're having trouble jump-starting your family's health, Dr. Oz has five strategies to help.

Step 1—Keep Nothing Off-Limits

"I know that sounds crazy, but it turns out when you make foods off-limits, you create a cult around them and the kids just want to get to them. And they're smart—they'll find it," Dr. Oz says.

The time to make decisions about food isn't when you lock cabinet doors, he says. It's when you're in the supermarket. "Don't even bring the stuff into the house," he says.