Obesity is not simply a result of over eating, the reasons are multiple and complex. As with any serious disease, correcting the problem requires medical attention.
Today, more than 65 percent of adults in the United States are overweight or obese. Obesity puts people at increased risk for chronic diseases such as heart disease, type 2 diabetes, high blood pressure, stroke, and some forms of cancer.
"Obesity" specifically refers to an excessive amount of body fat. "Overweight" refers to an excessive amount of body weight that includes muscle, bone, fat, and water. As a rule, women have more body fat than men. We invite you to read Understanding Adult Obesity, published by the National Institute of Diabetes and Digestive and Kidney Disease, for more information.
How is obesity measured?
Measuring the exact amount of a person's body fat is not easy. The most accurate measures are to weigh a person underwater or in a chamber that uses air displacement to measure body volume, or to use an X-ray test called Dual Energy X-ray Absorptiometry, also known as DEXA. These methods are not practical for the average person, and are done only in research centers with special equipment.
There are simpler methods to estimate body fat. One is to measure the thickness of the layer of fat just under the skin in several parts of the body. Another involves sending a harmless amount of electricity through a person's body. Results from these methods, however, can be inaccurate if done by an inexperienced person or on someone with extreme obesity.
Because measuring a person's body fat is difficult, health care professionals often rely on other means to diagnose obesity. Weight-for-height tables, used for decades, have a range of acceptable weights for a person of a given height. One problem with these tables is that there are many versions, all with different weight ranges. Another problem is that they do not distinguish between excess fat and muscle. According to the tables, a very muscular person may be classified obese when he or she is not. The BMI is less likely to misidentify a person's appropriate weight-for-height range.
Health care professionals are concerned not only with how much fat a person has, but also where the fat is located on the body. Women typically collect fat in their hips and buttocks, giving them a "pear" shape. Men usually build up fat around their bellies, giving them more of an "apple" shape. Of course, some men are pear-shaped and some women become apple shaped, especially after menopause.
Excess abdominal fat is an important, independent risk factor for disease. Research has shown that waist circumference is directly associated with abdominal fat and can be used in the assessment of the risks associated with obesity or being overweight. If you carry fat mainly around your waist, you are more likely to develop obesity-related health problems.
Women with a waist measurement of more than 35 inches and men with a waist measurement of more than 40 inches may have more health risks than people with lower waist measurements because of their body fat distribution.
Two people can have the same BMI but different body fat percentages. A bodybuilder with a large muscle mass and low percentage of body fat may have the same BMI as a person who has more body fat.
Bariatric surgery may be the next step for people who remain severely obese after trying non-surgical approaches, or for people who have an obesity-related disease. Surgery to produce weight loss is a serious undertaking. Anyone thinking about this type of surgery needs to understand the operation and the lifestyle changes you need to make.
You may be a candidate for surgery if you have a body mass index (BMI) of 40 or more; or a BMI of 35 and above, and a serious obesity-related health problem such as heart disease or type 2 diabetes. You can estimate your BMI by using our online calculator.