Weight and Body Shape

Excerpted from
The Body Shape Solution to Weight Loss and Wellness
By Marie Savard, M.D., Carol Svec

It would be impossible to miss the message that obesity is now epidemic throughout the world. During two weeks in February 2004 alone, headlines proclaimed: DOCTORS CALL FOR ACTION OVER OBESITY "TIMEBOMB"; KILLER HABITS "NEED URGENT ATTENTION"; FAT "THE NEW TOBACCO," HEART GROUP WARNS; ALARM SOUNDED ABOUT RISING RATE or OBESITY IN KIDS. The phenomenon is so far-reaching that the World Health Organization has coined a new word for this devastating health crisis: "globesity." We know that obesity is related to an increase in an individual's risk of heart disease, stroke, type 2 diabetes and the metabolic syndrome, and many types of cancer, not to mention gallbladder disease, osteoarthritis, depression, and gum disease. It slows us down, adds to back pain, makes it difficult to breathe, and generally reduces our quality of life. BuT how do we determine who is obese and who is not?

Although it seems like a simple question, medical professionals have debated the best ways to define "obese" for decades. Human beings are not as easily categorized as you may suspect. We have variations of height, bone mass, muscle tissue, and other factors that make our degree of fatness difficult to gauge. Nevertheless, a person is generally considered to be obese if she is carrying 25 percent more weight than what is considered optimal for good health.

Sure, individuals, cultures, societies, and professions all have different standards and definitions of overweight. But in the world of medicine, definitions become important if we want to help people identify their specific risks and take action to avoid the diseases related to fatness. The debate is still going on. Should we measure straight body weight, or is a calculation of weight by height more accurate? Some health professionals use calipers to pinch and measure the skin folds in certain areas of the body. Others will weigh a person on dry land, then dunk her in a pool of water and weigh her again. Because body fat weighs less in water than on land, a simple calculation can reveal what percentage of the body is fat and what percentage is lean muscle mass.

Now, the burgeoning issue of body shape has added a new wrinkle to that old debate, and it raises an interesting question: Do all kinds of obesity contribute to health risks, or just visceral obesity?

Weight and Body Mass Index (BMI)

Most of us are familiar with the concept of body weight. We stand on a scale and learn how much our body weighs in pounds or kilograms. I'll wager a guess that you know your current weight (within a pound or two). Most women do. It's a rare woman who can't tell me not only what she weighs today, but what she weighed in high school, in college, before and after having children, and on her last birthday. We've been trained over the last three decades to incorporate weight into our sense of self and, too often, self-worth. I can't tell you how many times I've told friends that they look terrific, and they replied with some version of, "Well, I'd look better if I could only lose five pounds." As if they didn't deserve a compliment because of their extra weight. Incredibly, some of my women patients have told me that they delayed making an appointment for a physical exam because they wanted to lose weight first ... or worse, they didn't schedule the physical at all because they couldn't lose the weight they knew they needed to lose, which I learned only if we happened to be standing on the same supermarket line! We pin so much of our sense of "goodness" and "success" on our current weight that we overlook the ultimate goal: good health.

Body mass index (BMI) was developed to acknowledge that a person's weight is related to her height. Rather than measuring weight in pure poundage, the BMI is a score that standardizes pounds-per-height. The scores are grouped into ranges that reflect who is "under-weight," "ideal," "overweight," or "obese." BMI allows us to see our place in the weight spectrum at a glance.

To find your BMI, find the row for the number closest to your weight on the vertical axis on the left side of the chart. Draw a light pencil line across that row, through all the numbers. Next, find the column for the number closest to your height on the horizontal axis at the top of the chart. Draw a light pencil line down that column, through all the numbers. The number in the box where the two pencil lines meet is your BMI. If your number falls in the shaded area (BMI 18.5 to 24.9), your weight is considered ideal." If your number falls above the shaded area (BMI below 18.5), you are considered underweight; if your number falls below the shaded area (BMI 25 and higher), you are considered overweight. If your BMI is 30 or higher, your degree of overweight is called "obese." (Please remember that that word - obese-is not a judgment, it is a scientific label.)

Although BMI is more stable and a better indicator of fatness than weight, its main weakness is that it doesn't take muscle mass into account. A lean, muscular bodybuilder has a dense, heavy body, and therefore can have a BMI that defines her as overweight even though her body fat is minimal. Still, BMI is the primary measurement used by researchers to define "overweight" and "obese" for clinical studies. Although health experts recommend that doctors use BMI to diagnose patients and recommend treatment, they rarely use it. Most women don't know or remember their current BMI number. That's probably because BMI is abstract-it doesn't slick as easily in the mind, and it's risks of diabetes and heart disease, it was only the visceral fat. This tells us that people who are apple-shaped and overweight are more likely to have metabolic abnormalities caused by their excess fat than any other group. However, it's important to note that lean apple-shaped twins had normal metabolism-good health was within reach just by losing weight!