Waisted: Abdominal obesity and your health
"How much should I weigh, doc?"
It's a common question, and an important one. It's common because about two-thirds of all Americans weigh more than they should. It's important because excess weight has serious consequences for health. Obesity is responsible for high levels of LDL ("bad") cholesterol and triglycerides. At the same time, it lowers HDL ("good") cholesterol. It impairs the body's responsiveness to insulin, raising blood sugar and insulin levels. And the consequences go far beyond an unflattering figure and a worrisome metabolic profile: obesity contributes to major causes of death and disability, including heart attacks, strokes, high blood pressure, cancer, diabetes, osteoarthritis, fatty liver, and depression.
All in all, obesity and lack of exercise are responsible for about 1,000 deaths in the U.S. each day. Faced with these risks, it's no wonder that you want to know how much you should weigh. But this common and important question is actually the wrong question. For health, the issue is not how much you weigh, but how much abdominal fat you have.
Methods have changed over the years. For decades, doctors relied on simple height and weight charts popularized by the Metropolitan Life Insurance Company. But when scientists recognized that what matters is not body weight but body fat, standards began to change. In the 1980s, measurements of skinfold thickness were all the rage. Next, doctors returned to a method established by the 19th century Belgian mathematician, Adolphe Quetelet. To evaluate body fat, this method depends on measuring height and weight, then dividing the weight (in kilograms) by the height (in meters) squared. Originally known as the Quetelet index, this technique is now called the body mass index (BMI), and it remains enshrined as the standard way to diagnose overweight and obesity.