THE NEW school year is upon us and instead of worrying about their children's clothes and sneakers, parents should be thinking about their kids' exercise and nutrition habits.

Experts have been saying for years what we all can see for ourselves -

we're in the midst of a childhood obesity epidemic. Like the proverbial elephant in the room, everybody can see it, but no one wants to say a thing.

Yet more of our children are struggling not only with their weight but with the diseases and health problems that go hand-in-hand with obesity.

The latest estimates are that as many as 15 percent of all U.S. children are overweight; for black and Latino children, that number jumps to 25 percent.

Despite what parents may think, "baby fat" can be a serious threat to your child's health. Every excess pound contributes to your child's risk for serious conditions such as heart disease, diabetes, high blood pressure, high cholesterol, sleep apnea, joint problems, reproductive problems, psychological and social difficulties.

So this year, don't stick your head in the sand, mom and dad, as your child's health risks increase. Instead, get busy and active, both in and out of school.

Make sure your child's school has a comprehensive fitness program and that physical education class is taken seriously. See to it that the physical education teacher has goals for your child, that the program teaches fitness-oriented lifestyles, and teaches responsibility for one's own health.

While you're at it, check out the lunch and or breakfast program and make sure your school is offering healthy options - plenty of fresh fruits and vegetables, not just cheap filler like bagels and pasta laden with fattening meats and heavy sauces.

One way to make a difference is to get involved with the "Time for Lunch" campaign, which officially begins on Labor Day with a national day of action. More than 250 "eat-in" demonstrations are scheduled in all 50 states.

"Time for Lunch" is a virtual march on Washington to send a clear message to Congress to invest in children's health by providing them with healthy food choices and habits. The campaign wants Congress to update the Child Nutrition Act, which is due for renewal this month.

More than 30 million children rely on the National School Lunch program. So, here's a chance to be heard and get real food into your child's school lunch program. For more information and to get involved go to the Web site at www.slowfoodusa.org/timeforlunch. You can sign an electronic petition and locate "Time for Lunch" events in the Philadelphia area.

But you don't need to wait for an act of Congress to get your family moving toward a healthier lifestyle. You can make a difference by doing more cooking at home. In the time you spend waiting in the average drive-through, you can cook a simple, healthy meal.

Philadelphians are fortunate because we have a ton of fantastic health, fitness and nutrition resources to support families. Many of these are free.

Here are a few no-cost or low-cost fitness activities that the entire family can enjoy:

Fairmount Park: Philadelphians are blessed with one of the world's largest municipal parks. It costs nothing to use it, for a family picnic or for participatory sports - play ball, walk, run, bike, hike or rollerblade.

Museums over movies: Take the kids to a museum instead of a sedentary activity like the movies - where you'll be tempted to eat buttery popcorn and drink sugar-filled soda, too. Because you generally do a lot of walking in a museum you'll also get a built-in low-impact cardio workout.

For discounts on Philadelphia attractions, visit the Philly Fun Guide at www.phillyfunguide.com and take advantage of the funsavers, which offer up to a 50 percent discount on theater, music, dance, sporting events and museum exhibits. You can sign up for free.

Here's a sample:

Philadelphia Museum of Art (www.philamuseum.org)

African American Museum in Philadelphia (www.aampmuseum.org)

Franklin Institute (www.fi.edu)

University of Pennsylvania Museum of Archaeology & Anthropology (www.museumupenn.edu)

National Liberty Museum (www.libertymuseum.org)

Independence Seaport Museum (www.phillyseaport.org)

Please Touch Museum (www.pleasetouchmuseum.org)

Morris Arboretum of the University of Pennsylvania (www.morrisarboretum.org)

Smith Playground: Located within Fairmount Park, Smith the Kids' Play Place provides children under 10 with free one-of-a-kind play experiences. Recently refurbished, this playground is an urban gem. It's located near 33rd and Oxford streets in the east park.

If you can afford to spend some money, there are dozens of fitness classes to meet the needs of young people. Here are just a few options:

Yoga Child (www.yogachild.net)

Philadelphia Kids Club (www.philakidsclub.com)

The 76ers Camp (www.sixerscamp.com)

The Mount Airy Bantams (www.leaguelineup.com/bantams)

The Living Arts Dance & Fitness Studio (www.livingartsdance.com)

Kimberly Garrison is a certified personal trainer and owner of One on One Ultimate Fitness in Philadelphia (www.1on1

ultimatefitness.com). E-mail her at kimberly@1on1ultimatefitness.com. Her column appears each Thursday in Yo!