We've all heard warnings, yet many of us keep gaining weight. More than half of American adults are overweight or obese, says the Centers for Disease Control and Prevention.

Childhood obesity is on the rise. Nearly 20 percent of U.S. children are obese. Three decades ago, that number was only about 7 percent.

The not-so-secret secret to weight loss is to burn more calories than you eat. This can be done safely and effectively by eating a healthy diet and exercising regularly.

Healthy bodies come in all shapes and sizes. Not all bodies are made to be thin. For some people, a healthy weight is higher or lower than the average weight listed on weight charts.

Each overweight or obese American spends $700 more a year on medical bills than trim neighbors, one expert says.

There is an epidemic of obesity in this country, health experts say. But what is obesity? How is it measured?

We've all heard warnings, yet many of us keep gaining weight. More than half of American adults are overweight or obese, says the Centers for Disease Control and Prevention (CDC).

Using body mass index (BMI), the National Institutes of Health (NIH) puts the definition of overweight at 25 to 29.9 BMI. A BMI of 30 and above qualifies a person as obese. A person with a BMI of 30 is about 30 pounds overweight, the equivalent of 221 pounds for a person who is 6 feet tall, or 186 pounds for someone who is 5-foot-6.