Dr. Oz and Dr. Jen Trachtenberg
From thumb sucking to infected belly button piercings, pediatrician Dr. Jen Trachtenberg has dealt with all kinds of bad habits that kids and teens tend to indulge in.

Dr. Jen shares with Dr. Oz tips for parents from her new book, Good Kids, Bad Habits: The RealAge Guide to Raising Healthy Children:

Eat breakfast. Parents need to set an example to help their kids develop healthy habits, starting first thing in the morning with breakfast, Dr. Jen says. Try to eat breakfast with your kids and encourage them to eat foods high in fiber, protein and healthy fat. "Kids have more energy, they concentrate better at school and do better on testing if they eat breakfast," Dr Jen says. If your kid won't eat a healthy breakfast, she says to mix their favorite sugary cereal with whole grain cereal.

Limit screen time. TV, computer and other "screen time" activities should be limited to about two hours a day. "You have to get your kids up and out and away from the TV," Dr. Jen says. Planning ahead and having games and activities ready for your kids will help you get them away from the TV.

Teach kids good hygiene. Dr. Jen says teaching kids good hygiene practices should start at a very young age to prevent them from contracting diseases and to help them develop socially. Teach your kids good hand-washing practices and oral hygiene, including flossing. Dr. Jen says developing these good habits now will become second nature to your child down the road.

End the pacifier habit and take it easy on thumb suckers. Some kids are still attached to pacifiers after their first birthday. Dr. Jen says the best way to break this habit is to stop the behavior cold turkey. You can hold some kind of "bye-bye pacifier" ceremony around a child's first birthday, Dr. Jen says. Dealing with thumb sucking is a little different; she says you shouldn't push a child to stop until they are ready. Usually a child will stop sucking their thumb around age 4 or 5, once they enter school.

Educate kids about tattoos, body piercings and sex. Dr. Jen says she has seen teens as young as 15 with body piercings and tattoos. It's important to educate your kids about the risk of contracting HIV and other diseases from dirty needles when getting a piercing or a tattoo at an underground shop or by a friend. Also, if your child wants to have a tattoo or a piercing done, you should find out what is motivating them and discourage peer pressure. As far as the birds and the bees talk is concerned, Dr. Jen suggests bringing it up at least by age 11 or 12. "The earlier you start, the better, especially for girls," she says. "Many start getting their periods now at age 9."

Encourage kids to be active. Fifty percent of kids, ages 12 to 21, are not active enough Dr. Jen says. Encouraging physical activity as a family is one way to keep your kids from becoming overweight. Also, physical activity doesn't have to take place outdoors. "It doesn't always have to be heart-pumping running around outside," Dr. Jen says. "You just want them to be moving around a little bit, moving their muscles and joints … and expending some energy."