A lot of attention has focused lately on how heavy Americans are becoming. In fact, more than 123 million Americans are overweight or obese, putting them at greater risk for cardiovascular disease, stroke, cancer and diabetes.
Women with more than 30 percent body fat and men with more than 25 percent body fat are obese. To measure body fat, health professionals use a variety of methods, including underwater weighing, skin-fold calipers, bioelectrical impedance, dual energy X-ray absorptiometry (DEXA) and air displacement using a device called the Bod Pod. The most accurate methods are underwater weighing and DEXA, but these are generally offered only by research institutions and universities. Calipers and bioelectrical impedance machines are widely used by fitness centers and weight-loss programs, but they are not as accurate.
It's important to note that it's not just how much extra body fat a person has, but where it is stored on the body that determines how risky the extra pounds are. People who are apple-shaped carry their excess fat mostly around the waist and are more likely to develop serious health problems than people who are pear-shaped and carry extra fat mostly in the hips and thighs. Overweight and obese conditions, however, regardless of fat distribution, markedly increase risk for disease and increased mortality when compared with people of optimal weight.
Scientists refer to having an apple shape as "central obesity." Its characteristic potbelly indicates that the internal organs are surrounded by fat, which poses a high risk for obesity-related diseases. Waist circumference is an indication of central obesity. A woman's waist should be less than 35 inches around and a man's less than 40 inches.
Central obesity can be an early warning sign of a condition called metabolic syndrome. People with metabolic syndrome have elevated blood pressure, high triglycerides, insulin resistance and low levels of HDL ("good") cholesterol. This combination of factors creates an especially high risk for stroke, cardiovascular disease and diabetes.
In addition to waist circumference, calculating body mass index (BMI) is a simple way to determine if body fat is in the healthy range. BMI is based on height and weight and correlates well with body fat level. A healthy BMI is between 18.5 and 24.9. A BMI of 25 to 29.9 is considered overweight, and 30 or greater is considered obese. To calculate BMI online, visit http://www.nhlbisupport.com/bmi.
People who know they would benefit by losing weight should cut calories, keep portions small and exercise. Lifestyle changes aren't always easy, but without action, people with excessive body fat face a future of poor health.
© 2014 Main Line Health