It's no surprise that the self-image and self-esteem of overweight children are generally quite poor. And this is only exacerbated by the teasing and ridicule of their peers ? a situation that, in these post-Columbine days, can result in much more than hurt feelings. Even if children aren't tormented into taking their frustration out on others, they may well take it out on themselves. In 1994, an Associated Press article told the story of 11-year-old Brian Head, an overweight child who shot and killed himself as a last resort against the ridicule of his classmates. Growing up can be difficult enough; growing up feeling isolated can be too much to handle.

Then, of course, there are the many physical consequences of obesity. In this country, tobacco causes approximately 400,000 deaths a year. Diet and inactivity are to blame for 300,000. According to the Surgeon General, in his 2001 Call to Action, death from obesity may now be as great as from poverty, smoking, or problem drinking. He warns that a significant increase in the risk of disease can be attributed to even a modest weight gain. (For example, a gain of only 11 to 18 pounds increases a person's chance of developing type 2 diabetes to twice that of those who haven't gained weight.) In fact, people who are obese have a 50 to 100 percent increased risk of premature death from all causes compared to individuals who are not obese.

The health risks of obesity are indeed numerous ? with many risks coming as a surprise to most people. We realize, of course, that heart disease can be caused by high blood pressure and/or high cholesterol, both of which can result from poor diet and lack of physical activity. Stroke is also commonly understood to be a possible result of obesity.

But did you know that many cancers (colorectal, prostate, breast, endometrial, cervical, ovarian, gallbladder) are also on the list of health risks for the obese and overweight? Dileep G. Bal, president of the American Cancer Society, maintains that at least one-third of all cancers can be attributed to poor diet, physical inactivity, and overweight. This is higher than any cause other than tobacco.

Here, in a nutshell, are some of the other health risks of overweight and obesity:

? Diabetes (insulin resistance, hyperinsulinemia)

? Sleep apnea (from extra folds of flesh in the throat obstructing airways)

? Respiratory disorders

? Decreased release of growth hormone

? Osteoarthritis

? Gout

? Musculoskeletal disorders

? Fatty deposits in the liver, leading to inflammation

? Early maturation

? Orthopedic problems

It's not a pretty list. But the scariest part may be that many of the unsafe behaviors ? and a number of the risk factors ? begin in childhood. Type 2 diabetes was formerly known as adult-onset diabetes, as it was previously unheard of among the young. It is now seen in record numbers among the young. And early onset of diabetes will most likely mean its complications also begin earlier in life. When adults develop type 2 diabetes, they suffer complications at about age 50; children with type 2 diabetes can expect to see complications at about age 20. (We currently spend approximately $96 billion annually treating diabetes, mostly due to its complications.)

And heart disease? As mentioned at the beginning of the chapter, this is no longer a concern of senior citizens only. Nor should we wait until middle age to start thinking about it! Whereas in the past heart disease risk factors were rarely seen in anyone under the age of 30, today it is becoming all too common to find them in children and adolescents ? even those without a history of heart disease in their families. Studies have shown that 40 percent of children ages five to eight have at least one risk factor, including hypertension. (Should we be using the words five-year-old and hypertension in the same sentence?) The first signs of arteriosclerosis ("hardening of the arteries") are also now appearing at age five! According to the Centers for Disease Control (CDC), the Bogalusa heart study found that 58 percent of overweight children had at least one additional risk factor for cardiovascular disease; and more than 20 percent had two or more risk factors.

In another study, Dr. E. Murat Tuzcu, director of the Intravascular Ultrasound Laboratory at the Cleveland Clinic Foundation, and colleagues looked at the arteries of 181 transplant recipients whose hearts were harvested from donors ages 13 to 55, all of whom had died not from disease but in car accidents or from gunshot wounds. These researchers discovered that one in six hearts from teenage donors had significant blockages (plaque) in at least one coronary artery delivering blood to the heart! Had they not died in accidents, following decades of plaque formation, these donors would have been likely candidates for heart attacks at 50, 40, or even 30.

The moral of the story is: Most of the chronic and deadly diseases of adulthood don't just suddenly appear.

The CDC tells us that chronic diseases account for seven of every 10 deaths in the United States and for more than 60 percent of our medical costs. Further, the lingering illness and disability common to many chronic diseases reduces the quality of life for millions of Americans. Today's most common chronic disease in the United States? It's obesity. The bad news is that there are 300,000 deaths a year in the United States alone due to low levels of activity and fitness. The good news is that they're due to low levels of activity and fitness ? something that's eminently "fixable."

Rae Pica is a children's physical activity specialist and author of Your Active Child: How to Boost Physical, Emotional, and Cognitive Development through Age-Appropriate Activity (McGraw-Hill, 2003). Rae speaks to parent and education groups throughout the North America. You can visit her and read more articles at http://www.movingandlearning.com.