Obesity
Definition
Although used interchangeably, "overweight" and "obese" do not mean the same thing. Obesity is a medical term meaning the storage of excess fat (adipose tissue) in the body.
Description
Often referred to as a disease, obesity is actually a sign of what may well be a spectrum of different kinds of disorders - genetic or environmental. In fact, there is no single definition of obesity. It may be simply an extreme degree of overweight - but a person can be overweight without being obese. A 250-pound, 6' linebacker, for example, may be overweight according to ordinary standards, but may actually have a below-average amount of body fat. In contrast, a person in a normal weight range but with very sedentary habits, could have a small muscle mass, be storing excess fat, and thus be classifiable as obese. About one-half of all Americans are above their ideal weight, as determined by standard tables, and for the majority of them, the excess weight is in the form of body fat, not muscle mass. Of this group, half exceed their ideal weight by 20 percent or more. Hence, they are classified as obese. Obesity has become epidemic in the U.S. and other developed countries. More than 58 million Americans are overweight, and that includes at least 1 in 5 children. Two principal risk factors that lead to obesity, poor nutrition and lack of physical activity combined, are the second leading cause of preventable death (tobacco is first). Obesity is associated with significant increases in risk for type II diabetes mellitus, hyperlipidemia, high cholesterol, coronary artery disease, degenerative joint disease and psychosocial disability. Certain cancers - colon, rectum and prostate in men; uterus, biliary tract, breast and ovary in women - are more prevalent in the obese.
Causes
Until recently, obesity was considered the result of a sedentary lifestyle and the chronic ingestion of excess calories. This may be the principal factor for many individuals, but there is evidence of strong genetic, metabolic and environmental influences in the development of obesity. Certain illnesses and medications also can cause obesity.
Diagnosis
A physical examination is usually sufficient to detect excess body fat. A complete medical history, including age at onset, family history, eating and exercise behavior, smoking, alcohol use and previous weight loss experience are all important. Less than 1 percent of all obese patients have an identifiable secondary cause of obesity (such as hypothyroidism and Cushing’s syndrome). Your physician may order blood tests, including fasting levels of glucose, cholesterol and triglycerides.
Treatment
Successful programs for weight loss reduction and maintenance should be started and followed under the care of a physician. The most important thing to remember is that if you eat less and exercise more, you will lose weight. A weight-loss program may include:
- Exercise (the Surgeon General has called for 30 minutes of physical activity on most days of the week)
- A low-fat, high-complex carbohydrate, high fiber diet
- Behavior modification to change eating behavior
- Social support
- Medications, both over-the-counter and prescription
It is very important to discuss all medications you are taking with your physician. Concern about side effects has diminished enthusiasm for appetite-suppressant drugs, particularly fenfluramine and dexfenfluramine, which carry serious risks. Individuals who have taken either should be evaluated by a physician. Phentermine remains available, but is approved only for short-term use. Although SSRI’s (serotonin specific reuptake inhibitors) have been discussed, studies have not confirmed their effectiveness for weight loss. A new medication, sibutramine (Meridia) blocks the uptake of both serotonin and norepinephrine. Although surgery is the last resort for the treatment of obesity, over 100,000 patients have chosen this form of therapy. Consensus recommendations are to limit surgical therapies to patients with a Body Mass Index (BMI) greater than 40. BMI is calculated by dividing the measured body weight in kilograms by the height in meters squared. To calculate your body mass index, follow these steps: Multiply your weight in pounds by 705; divide by your height in inches; divide this number by your height in inches a second time. You may also use an online BMI calculator at the National Heart, Lung and Blood Institute (http://www.nhlbisupport.com/bmi/). A normal BMI = 18.5-24.9; overweight = 25.0-29.9; obese = 30 or greater; and morbidly obese = 40 or greater.
Questions
I've always been overweight. Why should I worry about it now? Should I consider taking a medication for my weight condition? What effect will continuing to be overweight have on my newly acquired diabetes (if applicable)? What types of physical activity would you recommend? How can I find the time, social support and motivation to become more physically active? Do you recommend a specific diet? If so, what kind? I've lost weight before and regained it. How do I lose weight and keep it off now? Should I consider surgery?
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