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Know Your BMI

Technically, the problem is not overweight but overfat. Some chunky folks really are "all muscle" — although you're more likely to run into them at a weightlifters' convention than on the street. Women are overfat when their weight is more than 33- to 36-percent fat; men when it's over 20- to 25-percent fat. (The lower percentage is for people under 40, the higher for those 60 and older.)

It's hard to measure your fat percentage, however, unless you own an electronic body-fat scale ($60 to $120). Otherwise, you need a special test. The most reliable involves weighing yourself under water, where your buoyancy reveals how much of you is muscle, skin, and bones and how much is not. Another test measures the fat beneath your skin by pinching you with spring-loaded calipers.

Most people don't need to go to this trouble, however. Unless you're extremely flabby or muscular, you can use a rule of thumb called the Body Mass Index (BMI), which compares your height and weight.

To find your BMI, you can either plug your stats into this equation —

BMI = (Your Weight in Pounds x 703) / Square of Your Height in Inches

— or (much easier) use this nifty table or the Ideal WeightCalculator in DietPower nutrition software. (If you don't already have DietPower, you can begin using a free trial of the complete program right now by clicking here.)

Porkiest Man in the Senate

Once you know your BMI, you also know whether you're "underweight," "normal weight," "overweight," "obese," or "severely obese." Below are the official definitions, along with a few celebrities in each class.

• You are underweight if your BMI is under 18.5. Fashion model Kate Moss (15.7) is underweight. So are author Joyce Carole Oates (15.5) and former First Lady Nancy Reagan (18.2). So were musician Tommy Dorsey (15.5) and Ethiopian emperor Haile Selassie (17.2). (Underweight carries health risks of its own. Click here for advice.)
• Your weight is normal or healthy if your BMI is 18.5 to 24.9. Prince Charles (22.2) is normal-weight. So are ballerina Margot Fonteyn (19.2), financial columnist Sylvia Porter (19.9), and Olympic skater Scott Hamilton (19.5).
• You're overweight if your BMI is 25.0 to 29.9. Rap singer Queen Latifah (25.8) is overweight, as are fitness guru Richard Simmons (25.0), former Iraqi dictator Saddam Hussein (31.4, if he hasn't gained or lost weight in jail), and (yes, it's true) Hollywood hunk George Clooney (29.4).
• You're obese if your BMI is 30.0 to 39.9. Anthropologist Margaret Mead (32.0) was obese. Others in this group include American Civil Liberties Union founder Elizabeth Gurley (33.3); Edward M. "Ted" Kennedy (34.2 — our most corpulent U.S. Senator); conservative radio-talk-show host Rush Limbaugh (35.3); and King Taufa'ahau Tupou IV of the Polynesian island of Tonga (37.5).
• You are severely obese if your BMI is 40.0 or higher. Weight-loss guru Susan Powter (40.7) was severely obese before she dropped 133 pounds. Her peers include women's suffragist Elizabeth Cady Stanton (40.7), singer Jennifer Holliday (56.6) before she lost 200 pounds, musician Fats Waller (43.2), and actor Marlon Brando (44.3).

Lard Almighty

Over the past few decades, Americans have been bulking up in amazing numbers. Since 1980, the obesity rate has doubled and overweight has climbed 40 percent. Two-thirds of U.S. adults are now officially overweight, and half of those are obese. Among major industrialized nations, we are now officially the fattest.

Overweight used to be a mark of poverty and ignorance, but this is changing. Obesity rates have risen faster among the affluent and college-educated. Sex differences, too, are changing. Nowadays, women — especially in middle age — are almost as likely to be overweight as men.

Geographical skews haven't changed. The skinniest people still live in New England and the mountain states, the tubbiest in the South. The fattest state is Mississippi, with a 24.3-percent obesity rate; the leanest Hawaii, at 15.1 percent.

Public-health authorities blame America's weight gain on three trends:

• Food is plentiful and cheap. Thanks to globalized competition and more efficient farming, processing, packaging, and retailing, the cost of feeding an average family (in inflation-adjusted dollars) is 5- to 10-percent lower than 30 years ago. Meanwhile, the number of items in a modern supermarket has passed more than 30,000.
• People are busier. A freer labor market compels people to work more hours per week. As a result, they eat oftener in restaurants and out of packages — where the seller, not the buyer, controls the helpings. They also have less room on their schedules for burning off those calories. Three-quarters of adults get no regular exercise.
• Portions are bigger. Because food is cheaper than labor, marketers find it easier to raise profits by pushing bigger helpings than by serving more meals. That's why "super-sizing" has swept the fast-food industry. But homemade portions are bigger, too. According to a study published in the Journal of the American Medical Association, the average fast-food burger has grown from 6.1 ounces to 7.2 ounces in 20 years — but Mom's burger has swelled even more, from 5.7 to 8.4 ounces. Meanwhile, the average dessert has risen from 4.2 to 4.8 ounces.

An Expensive Problem

Most people know that obesity can lead to heart attack. Many understand that fatty foods contribute to cancer. But obesity carries many other risks. Here's a partial list:

*HUR-soot-izm: excess facial and body hair.

According to the U.S. Surgeon General's office, obesity and inactivity are now the nation's second leading killer, after tobacco use. They are believed to cause 300,000 early deaths each year — seven times as many as auto accidents.

Obesity also raises health-insurance rates. According to a 2002 study by the Rand Corporation, annual hospital and outpatient spending for an obese adult averages $1800, versus $1400 for a normal adult. Other costs bring the nation's yearly bill for obesity to at least $100 billion, or $950 per household.

What Are Your Odds?

Population studies clearly show that overweight shortens lives. According to the Surgeon General, if your BMI is 30 or higher, your chances of premature death rise 50 to 100 percent. A 1999 study at Duke University concluded that overweight cuts life expectancy by one year; severe obesity by four years.

Researchers also know the odds for specific health problems. Here's a rundown, complete with sources:

Arthritis. For every two pounds you gain, your risk of osteoarthritis goes up 9 to 13 percent.¹ If you're female and obese, your risk is almost four times normal.²

Birthing problems. Obesity makes you 13 times more likely to have an overdue birth, long or induced labor, or blood loss during birth.²

Breast cancer Gaining 45 pounds or more after age 18 makes you twice as likely to develop breast cancer after menopause.² Gaining weight after menopause may also increase the risk.²

Diabetes. Gain 11 to 18 pounds and your risk is double that of someone who doesn't gain weight; gain 44 pounds and your risk is four times higher.¹ Reach a BMI greater than 35 and the risk is nearly seven times higher.²

Endometrial cancer. If you are obese, your risk of endometrial cancer is three to four times higher than normal.² If your BMI is 34 or greater, your risk is more than six times higher.¹

Gallbladder disease. If you're a woman, obesity makes you twice as likely to develop gallstones.²

Heart disease. If you're male, gain 10 to 20 pounds and your risk increases 60 percent; gain 22 pounds and it increases 75 percent.¹ If you're a woman, gain 10 to 20 pounds and it increases 25 percent; gain 44 pounds> and it nearly triples.¹ If you're severely obese, symptoms of heart disease (chest pain, shortness of breath) will develop seven years earlier than otherwise.³ If you already have heart disease, you will die four years earlier if you're obese.³

Hypertension. If you're obese, you are twice as likely to have high blood pressure.¹ If you're severely obese (BMI over 40), you're nearly four times more likely to have it.²

Incontinence. Obesity is a major risk factor for urinary stress incontinence,² which causes leakage during excitement, fright, or laughter.

Menstrual problems. Severe obesity triples your risk of menstrual disturbance.²

The Potbelly Factor

To get an even clearer picture of your weight risks, you need to factor in your waist size. Excess fat is more dangerous in the abdominal cavity than on your hips. Or, as weight-loss experts often put it, "You're better off pear-shaped than apple-shaped."

Your waist measurement is not your pants size. To gauge accurately, position the tape midway between the top of your hip bone and the bottom of your ribcage (usually close to the navel) and tighten it just enough to prevent slippage — if it's squeezing you, you're cheating. Don't suck in your gut, and don't hold your breath — take the measurement at the end of a normal exhalation.

Is your waist size a risk? That depends on your sex. For men, the potbelly factor kicks in when your waist passes 40 inches; for women, when it exceeds 35 inches.

Abdominal fat is risky even if your BMI says you're "healthy." In other words, if you're skinny but have a potbelly, do something about the belly.

The Couch Potato Factor

Even if you're perfectly trim, you're more likely to die early than a fat person who gets a lot more exercise. That's the conclusion of a landmark study published in 1999 by Dr. Steven Blair and colleagues at the Cooper Institute.*

Blair studied 25,000 middle-aged men and 8000 women for a decade. He monitored the subjects' fat content and BMI. He also gauged their degree of fitness, using standard treadmill tests. And he watched to see how well they survived.

Results: After ten years, twice as many normal-weight couch potatoes had died as those who were obese but fit. The risk of inactivity far outweighed that of obesity. In fact, among people with high blood pressure, low fitness elevated death risk more than smoking, high cholesterol, and obesity combined.

"I don't mean that exercise eliminates every health risk," Blair told a meeting of the Association for the Study of Obesity in 2001, "but you can stay overweight and obese if you are fit and be just as healthy, in terms of mortality risk, as a lean, fit person."

Blair himself is stocky and about 30 pounds overweight, but keeps in shape by jogging 45 minutes a day. He said most people could maintain fitness with 30 minutes of brisk walking per day. (More recently, government authorities have begun recommending 60 minutes a day. See "I'm Supposed to Exercise How Much?" in the September 2002 issue of DietPower's newsletter, Piping Hot!.)

Other Factors

Besides inactivity and abdominal fat, other conditions can magnify your risk of death from overweight. The most important are smoking, a diet high in fat or low in fruits and vegetables, high blood pressure or cholesterol, and preexisting diabetes or heart disease.

Your Overall Risk

The American Obesity Association has developed a one-minute "Weight Wellness Profile" that weighs all of the factors discussed above. Most people who score higher than 3 in the profile could benefit from weight loss, additional exercise, or both. To get your profile, click here.

The Best Weight-Loss Method

As many studies have shown, quick weight loss and fad diets don't work. They may yield amazing results, but only for a few weeks or months. In more than 90 percent of cases, the weight comes back. And according to some studies, repeating this cycle may be riskier than staying overweight.

The only way to lose weight permanently is slowly, by lowering your calorie intake a little or burning a few more calories in exercise. Getting more calories from carbohydrate or protein and fewer from fat may also help, partly because 100 calories worth of protein or carbs is a lot bulkier and fills you up better than 100 calories worth of fat.

Lowering your fat intake and eating less or exercising more will take a little effort at first — just as wearing your seat belt did. But in time, it will be a habit instead of a chore. And you'll be the picture of health.