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 BMI greater than 30 are considered obese.

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

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.

The health care provider will perform a physical exam and ask questions about your medical history, eating habits, and exercise routine.

Skin fold measurements may be taken to check your body composition.

Blood tests may be done to look for thyroid or endocrine problems, which could lead to weight gain.

A combination of calorie restriction and exercise (when adhered to) appears to be more effective rather than either one alone. Sticking to a weight reduction program is difficult and requires a lot of support from family and friends.

Even modest weight loss can improve your health. It is important to work with your health care provider or dietician to develop a plan that is best for you. For most people, weight can be lost by eating a healthier diet, exercising more, and adopting new behaviors such as keeping a food diary, avoiding food triggers, and thinking positively.

There are many over-the-counter diet products. Most do not work and some can be dangerous. Before using one, talk to your health care provider.

Prescription weight loss drugs are available. Such medicines include subutramine (Meridia) and orlistat (Xenical). Ask your health care provider if these are right for you.

Surgery may be an option for persons who are morbidly obese and who cannot lose weight using other methods. Weight loss surgery, such as placing adjustable bands around the stomach and gastric bypass surgery, can significantly improve weight and health in the right candidate. Talk to your doctor to learn if this is a good option for you.

Many people find it easier to follow a diet and exercise program if they join a group of people with similar problems.

See: Eating disorders - support group

Medical problems commonly resulting from untreated obesity and morbid obesity include:

• Diabetes
• Hypertension
• Heart disease
• Stroke
• Certain cancers, including breast and colon
• Depression
• Osteoarthritis

Obesity can lead to a gradual decrease in the level of oxygen in your blood, a condition called hypoxemia. Persons who are obese may temporarily stop breathing while asleep (sleep apnea). Decreased blood oxygen levels and sleep apnea may cause a person to feel sleepy during the day. The conditions may also lead to high blood pressure and pulmonary hypertension. In extreme cases, especially when left untreated, this can lead to right-sided heart failure and ultimately death.

Schedule an appointment with your health care provider if you or your child are obese or gaining weight at an extremely rapid rate. Remember that catching the problem early is much simpler than trying to fix it after the person has gained an excessive amount of weight.

A healthy diet and regular exercise can help prevent weight gain. Increase your daily activity. Take the stairs rather than the elevator, or walk instead of driving (when possible).

See also:

• Exercise and weight loss
• Losing weight
• Weight management

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