Definition of Obesity:

Obesity is a term used to describe body weight that is much greater than what is considered healthy. If you are obese, you have a much higher amount of body fat than lean muscle mass.

Adults with a body mass index (BMI) greater than 25 but less than 30 are considered overweight.

Adults with a BMI greater than 30 are considered obese.

Anyone more than 100 pounds overweight or with a BMI greater than 40 is considered morbidly obese.

Causes, incidence, and risk factors:

Rates of obesity are climbing. The percentage of children who are overweight has doubled in the last 20 years. The percentage of adolescents who are obese has tripled in the last 20 years.

Consuming more calories than you burn leads to being overweight and, eventually, obesity. The body stores unused calories as fat. Obesity can be the result of:

• Eating more food than the body can use
• Drinking too much alcohol
• Not getting enough exercise

Certain thyroid problems may also lead to signficant weight gain. Genetic factors play some part in the development of obesity -- children of obese parents are 10 times more likely to be obese than children with parents of normal weight.

Obesity is a significant health threat. The extra weight puts unusual stress on all parts of the body. It raises your risk of diabetes, stroke, heart disease, kidney disease, and gallbladder disease. Conditions such as high blood pressure and high cholesterol, which were once thought to mainly affect adults, are often seen in children who are obese. Obesity may also increase the risk for some types of cancer. Persons who are obese are more likely to develop osteoarthritis and sleep apnea.