No doubt you’ve heard the statistics: At least one American child in five is overweight. The percentage of overweight children has more than doubled since 1970.

And it’s painfully clear that much of the American lifestyle isn’t conducive to providing kids with healthful foods and opportunities to exercise.

“It’s a complex problem, but the solution is simple,” says Colleen Thompson, a registered dietician. “Not easy, but simple. Your child must eat more healthfully and exercise more. It’s the small, day-to-day decisions you make for your children that, taken together, comprise the solution. And becoming aware of those decisions is the first and most important step.”

Thompson and Ellen Shanley, M.B.A., R.D., have coauthored a book, Overcoming Childhood Obesity, aimed at helping parents create a healthful home environment complete with proper nutrition and exercise. The authors write that by changing a child’s eating behaviors and increasing physical activity, parents can improve their health and reduce the risk of obesity. Of course kids have different needs at different ages, so the book is divided into chapters by age group. Sample menus and exercise strategies are also included. Following are some tips from the authors.

• Insist that kids eat a healthy breakfast. Starting the day out right nutritionally helps jump-start the metabolism. Kids who don’t eat a good breakfast tend to overeat at lunch.

• Limit fast food forays. It’s easy to succumb to simple solutions, but you have to set time aside for healthy meals. If it’s unavoidable, consider sharing an adult-sized meal and set an example about reasonable portion sizes.

• Bring back civilized family meals. Modeling the proper place of food in our lives is crucial, Thompson says. “Remember, it takes up to 20 minutes for the brain to tell the body it’s full. Rushing through meals leads to overeating.”

• Let kids take control in the kitchen. Children should be active participants, not passive recipients, in all aspects of meal time. Research reveals that children may eat up to 25 percent less when they serve themselves.

• Make exercise a must for everyone. This can mean anything from walking around the block or going on a weekend hike. Yes, that means you have to get off the couch, too! Shanley points out, “The good news is that what’s fun for kids is usually fun for adults, too. And going on a family bike ride is certainly a better way to connect emotionally than sitting around in front of the television.”

• Practice what you preach. Children learn from watching you. They want to eat what they see you eating. Their attitude about exercise is modeled after you. “You might find that making a commitment to improve your child’s health is the best thing that ever happened to yours,” Thompson says.