Aug. 18, 2008 — -- Are you apple-shaped or pear-shaped?
Most women (and men for that matter) understand intuitively whether their bodies tend to store fat around their waists (forming an apple shape) or lower down around their hips, thighs and buttocks (forming a pear shape in women). But few of us understand the dramatic impact body shape has on our current health and risk of future disease.
A number of recent studies have shown that it is your waist size and body shape rather than how much you weigh or tip the scale that best predicts your risk for a number of chronic diseases. For example, a study published in this week's Archives of Internal Medicine found that while only half of the obese patients studied had metabolic abnormalities that placed them at much greater risk of heart disease, a full quarter of the normal weight adults had these same worrisome metabolic risks as well.
Why the risk in normal weight adults? Experts concluded that waist size may be much more important in determining heart risk than body weight. A normal weight individual can have a greater waist size -- and therefore a greater health risk -- than an overweight but smaller-waisted friend.
The metabolic abnormalities that were studied included high blood pressure, high triglycerides and low HDL cholesterol (the good cholesterol) levels. If you have these metabolic factors, chances are you are apple-shaped. In fact, I call the metabolic syndrome the "apple-syndrome" because having an apple shape is a necessary part of the mix.
One of the largest worldwide studies on heart risk factors ever, referred to as The Interheart Study, found that a person's waist-to-hip ratio (WHR) was three times more powerful a predictor of heart disease risk than body mass index (BMI). An editorial in the Journal of the American Medical Association warned physicians that even their normal weight patients who have apple shapes should be screened for heart disease.
So do you know your WHR? How about your waist size and body shape?
Determining your body shape is easy: First, measure around your waist to get your waist circumference. If you have a visible waist, measure around the smallest part. If you don't have an obvious waist, measure around the largest part of your middle, or about one inch above your navel.
Next, measure around the widest part of your lower bottom to get your hip circumference. Divide the first number by the second to get your waist-to-hip ratio (WHR).
For women, if your WHR is 0.80 or less, you are a "pear." If your WHR is greater than 0.80, you are an "apple." For men, a WHR of greater than 0.90 means you are an apple and at increased heart risk too. If your WHR is 0.90 or less I would call you a "healthy apple." I have found that men don't like to be referred to as pear-shaped.
Many doctors rely on waist size only to predict health risk. For women, a waist size of more than 35 inches means generally way too much visceral fat. For men, a waist size of more than 40 inches is considered risky.
Although we've known for decades that these different body shapes existed, only now are their causes and related health risks becoming clear. The startling discovery is that the areas of our bodies where we are genetically and hormonally predisposed to store our fat make all the difference.
Subcutaneous fat, being closer to the surface, is always easy to see. Visceral fat, on the other hand, is not always visible from the outside. It jams up against the intestines, kidneys, pancreas and liver (and sometimes even inside the liver). We all have some visceral fat because it protects our internal organs, acting both as shock absorber in case of trauma, and as insulator to help us conserve body heat. While some visceral fat is necessary, too much can create serious health problems.
Most people think of fat as inert material, much like the rind of fat surrounding a steak. But fat is actually living, breathing, hormone-producing tissue. Fat is critical for survival because it stores food energy, and because it helps regulate body functions through the give-and-take of chemical communications with the central nervous system.
Subcutaneous fat may be visible and annoying, but it is relatively harmless. In fact, fat in the pear zone -- hips, thighs and buttocks -- helps to protect us from disease and is hard to lose. Scientists are still studying this fat to try and understand exactly why it is protective. Subcutaneous fat is a ready supply of energy or fuel only when we are pregnant, breast-feeding or starving.
Excess visceral fat, on the other hand, can be dangerous. Visceral fat is more metabolically active than subcutaneous fat, and most of what it does is harmful to the body.
Visceral fat decreases insulin sensitivity (making diabetes more likely), increases triglycerides, decreases levels of HDL cholesterol (the good one), creates more inflammation and raises blood pressure -- all of which increase the risk of heart disease. Instead of trapping fat, visceral fat releases more of its free fatty acids into the blood stream, further increasing the risk of both diabetes and heart disease.
The overall effect of excess visceral fat is that it creates a physical environment that is primed for heart disease and stroke, and greatly increases the risk for certain estrogen sensitive cancers such as post-menopausal breast and endometrial cancer. This is why apple-shaped women and men, who carry their weight around their waists, have an increased risk of metabolic and vascular diseases.
No matter which body shape you have, how old you are or how much you weigh, there are many things you can do to decrease your personal disease risk. Diet and exercise are only part of the equation; medical monitoring is critical, as is a change in mindset.
Women need to stop thinking of their weight problems and learn to accept themselves as women with figures. Doctors need to get in the habit of measuring waist size and body shape and not focus only on body weight. Men need to pay heed, as body shape and waist size is important for them too.
My top tips for getting started:
My final tip: Release guilt! Your body shape is not your fault. We are all born with a genetic propensity to have a particular body shape. Full-figured, pear-shaped women will never have slender thighs, and apple-shaped women will never have an hourglass shape or washboard abs -- it is simply not possible, no matter how much you exercise or diet. Plus, there are some very real body shape changes toward a more apple shape that normally occur after each pregnancy and at menopause.
Nature, it seems, is determined to eventually make apple shapes of us all.
To learn more about the importance of body shape, visit www.DrSavard.com.
As always, I welcome your questions and comments.
Dr. Marie Savard is an ABC News medical contributor. Savard's most recent book is "Apples and Pears: The Body Shape Solution to Weight Loss and Wellness."