Fat

Fat

In many remote cultures, even today, fat is beautiful. In some societies women put on pounds in order to make themselves more attractive. They''''re happy to see excessive fat on their buttocks, a condition called steatopygia. Some tribes and villages reserve the best foods for girls who are approaching marrying age. The biggest in girth make the most desirable brides.

It was like that in primitive times, too. Back before farms and supermarkets, food was hunted and gathered, not raised. Famines were bad then and fat was good. Body fat kept our ancient ancestors alive--the equivalent of carrying their own personal grocery store.

Fat is the body''''s in-house hoard of food. It''''s pure stored energy. But most women deplore that extra bonus, especially when they''''re confronted in the media with supermodels Cindy, Christie and Kate. Seeing their clothes-hanger bodies promoted as "ideal," too often we succumb to the fashion world''''s very narrow definition of beauty.

"Living organisms have been around a lot longer than the fashion industry," says Phillip Sinaikin, M.D., author of Fat Madness and a psychiatrist in Longwood, Florida, who specializes in addiction and dieting. "Our bodies say that survival still outweighs looks. Biology is reality."

Fat-Fertile Fields

Compared with men, women bear an extra burden of body fat. On average we have about 8 percent more body fat than most men, which makes sense since we''''re designed to carry reserves for childbearing. So we pack an extra 120,000 calories--stored as fat--to see us through any situation.

There''''s a relationship between fat and hormones. A woman needs to tote at least 16 percent body fat to produce estrogen, the hormone that''''s essential for conception.

It works the other way, too, with some hormones promoting fat storage--others discouraging the process. "Estrogen promotes body fat storage," says Richard S. Surwit, Ph.D., professor and vice-chairman of the Department of Psychiatry at Duke University Medical Center in Durham, North Carolina, "and testosterone promotes lean muscle mass."

What Are the Risk Raisers?

The fat that women carry--generally on their hips, thighs, breasts and buttocks--is fairly innocent stuff, says Joanne Curran-Celentano, R.D., Ph.D., associate professor of nutrition at the University of New Hampshire in Durham and nutrition research coordinator at the Center for Eating Disorders Management in Dover. "It''''s subcutaneous fat--right under the skin." For the average woman this body fat makes up 20 to 25 percent of body weight. (Men''''s subcutaneous fat averages 15 to 20 percent of their weight.)

There is another kind of fat that puts us at risk of all sorts of health complications: abdominal fat. It doesn''''t feel soft and flabby like subcutaneous fat does. It''''s hard and unyielding, formed by deep, visceral fat packed around internal organs.

"Visceral fat is associated with blood sugar problems, adult diabetes, high blood pressure, high cholesterol and heart disease," says Dr. Curran-Celentano. We know what visceral fat looks like on men. They tend to put on weight in the abdomen in the form of the classic potbelly. Women tend that way, too, once they reach menopause.

Although abdominal fat is associated with increased health risks, it has one advantage. It''''s known to be more metabolically active than fat on the hips and thighs, which means that abdominal fat is somewhat easier to take off than fat in the other areas. "It accumulates faster, but it also breaks down faster than fat on the thigh or butt," says Jill Kanaley, Ph.D., assistant professor of exercise physiology at Syracuse University in New York.

"Activity--exercise--can turn it all around," says Dr. Curran-Celentano.

Why It''''s So Hard

Man or woman, beer belly or thunder thighs, 1 out of every 3 Americans is overweight. And more than 50 million people are on diets. They all know how hard it is to get rid of fat. But why?

Let''''s take a look at a fat cell--an adiposite, as researchers call it. That fat cell is just 1 of 30 or so billion that you have in your body. Together all these cells make up the adipose tissue. Because adipose tissue is such a health threat, molecular scientists and researchers have looked hard at the behavior of the fat cell to find out how we can shed our high-risk fat easier and faster.

"A fat cell looks like a little bag full of oil," says Dr. Sinaikin. In that bag is both fat that''''s produced by our bodies and fat that we eat in our diets. (Both kinds of fat are called lipids.)

Scientists have learned that even though we''''re all born with a certain number of fat cells, that number increases during infancy and again right before puberty. After that, most of us won''''t make any more fat cells unless we gain more than 160 percent of our ideal weight. If your ideal weight is 130 pounds, for instance, you wouldn''''t be adding any more fat cells until you reached 208 pounds.

The Abdominal Slow Man

A fat cell is like a balloon--it can expand and contract. If we overeat and underexercise, the energy we store as fat makes us (surprise!) fat. And sluggish. When fat cells fill up, they don''''t do their work well. When they should be thinning excess blood sugar out of the bloodstream and escorting dietary fat toward the nearest exits, they lumber along, barely doing their jobs. The worse they perform, the more vulnerable we become to problems such as diabetes and heart disease.

When we diet, says Dr. Sinaikin, the body calls on those stored reserves of fat for fuel and empties out those swollen fat cells. "Your fat cells can shrink a thousandfold, and as they get smaller, you get smaller."

But your body isn''''t crazy about either diets or starvation. "Dieting goes against all the trends in evolution," Dr. Sinaikin says. "All those cells cry, ''''Oh my God, we''''ve run out of food. I have to motivate this mechanism to survive.'''' So they create the state called hunger."

Yes, but what about our skinny sisters and slim friends--those lucky ducks whose fat cells never expand? They can eat till the cows come home--then eat the cow, too. How come?

Jeans and Genes

Researchers at Rockefeller University in New York City and Duke University are looking at the genetic stitching that helps decide the size of our jeans and the span of our thighs. They''''ve found a gene that tells us when we''''re full, a hormone that makes us burn excess fat and a metabolic defect that tampers with our ability to burn fat. Dr. Sinaikin and Dr. Surwit are intrigued by the role a substance called brown fat plays in the fat picture, too.

So far, most of what we know about brown fat comes from animal studies at Duke. When a mouse mom leaves her nest to forage for food, her babies burn brown fat for heat while she''''s gone. In other words, it''''s the fat that''''s quickly consumed for survival rather than stored.

As in mice, brown fat in humans is made up of fat cells that burn fat rather than store it. Those adults who seem to be able to eat a lot without gaining weight may have a larger-than-usual proportion of brown fat. So your fortunate friends who "have a high metabolism" or "burn up everything they eat" may in fact be walking storehouses of brown fat.

Dr. Surwit speculates that people are born with a genetic tendency to store certain amounts of fat. "It''''s clear as day that it''''s passed on from parent to child," he says. "There are thin families and fat families."

Sometimes the genetic factor is clear in a whole ethnic group, Dr. Surwit observes. "Native Americans probably have the greatest problem with obesity of any group, and also with diabetes. Seventy years ago, though, they had no problem. They may have developed genes to deal with repeated famines, which allowed them to store fat easily when food was available. What was an advantage to them in a time of scarcity is now a disadvantage in a time of plenty."

Dr. Sinaikin thinks that heredity carves about 30 percent of our body shape. And it''''s heredity that probably sticks us with a set point--the weight that we tend to maintain, through thick and thin and diet and exercise.

But the other factors that control size and shape are more likely to be within our control. "Genes do not determine what you''''re going to have for dinner tonight or how much you''''re going to exercise," says John P. Foreyt, Ph.D., director of the Nutrition Research Clinic at Baylor College of Medicine in Houston and author of Living without Dieting. Only you can regulate that, of course. What you decide to eat or do will influence every fat cell in your body.

Measuring Up--And Out

How much body fat is too much? Probably anything over 30 percent of your total weight is unhealthy and needs to be reduced, says Bryant Stamford, Ph.D., professor and director of the Health Promotion Center at the University of Louisville.

Trouble is, you can''''t drop a quarter in a body fat scale and get an instant readout--because such a handy-dandy device doesn''''t exit. The most reliable method--underwater measurement--is not widely available. More often a doctor will use calipers to pinch an area of skin and measure the adipose tissue in that area. Or she might measure by a method called bioelectrical impedance to find out how long it takes a painless current to go through the fat of your entire body. Electrodes are placed on your toes and fingertips. The more fat you have on your body, the slower the current. But neither the calipers nor electrical impedance methods are entirely accurate.

A pair of measurements that you can take at home, though, can give you a reliable figure for percent of body fat. These measurements are your weight and your height--which you can use to chart your body mass index, or BMI.

The BMI, a ratio of height to weight, is determined by a mathematical formula: Divide your weight (in pounds) by your height squared (using inches). Multiply the resulting number by 705. (If you would rather shortcut the math, see "Finding Body Mass Index."

Your BMI, doctors say, should be somewhere between 19 and 30. One large-scale study--the Nurses'''' Health study, based at Harvard University and Brigham and Women''''s Hospital in Boston and involving 115,886 women--points to a BMI below 21 as ideal for preventing heart disease in women. The study showed that there was no elevated risk of heart disease among women whose BMIs were under 21. But for women whose BMIs were 21 to 25, the risk was 30 percent higher. Also, the risk of heart disease soared 80 percent higher for women having a BMI of 25 to 29.

In the same study, researchers found that the weight-related risk of cancer begins to rise among women whose BMI was 26, 27 or higher.

What''''s Your Ratio?

While BMI is one good measure of fat-related risk, it doesn''''t tell the whole story. The fat most associated with health risks is on the upper body--from the abdomen upward. You can judge whether you have too much of it by comparing your waist measurement to your hip size.

* First measure your waist. The place to measure is at the midpoint between your bottom rib and hipbone.

* Measure your hips at their widest point. When you have these two numbers, divide the waist measurement by the hip measurement.

The resulting number is your waist-to-hip ratio (WHR). Although scientists can''''t agree on the exact numbers to target, most doctors agree that any number below 0.80 is optimal.

Note: WHR isn''''t very reliable for women who are very thin or very overweight.

With one number for your BMI and a second for the waist-to-hip ratio, you can then use the "Healthy Weight Target" to help you evaluate your fat-related health risk.

Being a Smart Goalie

While fashion styles come and go, our bodies aren''''t meant to shed fat at the blink of an eye.

Whatever your weight-loss goal, it should be reasonable. "People with moderate weight problems will never be as lean as some of their friends," observes Dr. Surwit. "But they can keep themselves reasonably lean--and healthy--with low-fat diet and exercise." (For tips on how to do that, see "Insights on Successful Slimming" on page 282.)

Meanwhile, to get started on slimming, here are some guidelines to keep in mind.

Get real. A 10 percent loss of body weight is enough to improve a health risk profile. No matter what you weigh, "you can lose about 10 percent without a whole lot of difficulty," says Dr. Foreyt. Then, if you keep that off for a year, set another 10 percent goal. "Focus on feeling good rather than looking good. Ask yourself how your exercise and diet program feels in day-to-day functioning."

Make like a tortoise. Weight control is a long haul. "There isn''''t any magic solution," says Dr. Curran-Celentano. "It takes a lot of hard work and strong will to be able to reverse the condition that led to excess weight gain."

Weight should come off slowly. Any loss over two pounds a week is probably the result of an untenable program, she notes, so be patient with yourself.

Commit to ten weeks. It takes time to break old patterns and establish new ones. "Habits are incredibly powerful," says Dr. Sinaikin. If you''''ve been having three butter pats on your toast every morning, and you switch to a teaspoon of all-fruit jam instead, it will take weeks before you''''re used to the new routine.

You should pledge your body to ten weeks of effort, experts advise. When you get past three months and you''''re still eating low-fat, you''''ve probably established the healthy new behavior, says Wayne C. Miller, Ph.D., professor of exercise science at George Washington University Medical School in Washington, D.C.

The Key to the Kingdom

Fasting, starvation and measuring out your food with coffee spoons is not the way to shed and keep off fat. Besides, "It''''s not overeating that''''s the biggest problem," says Dr. Curran-Celentano. It''''s a well-documented fact that the number of calories an overweight woman eats isn''''t much greater than the number on a skinny person''''s plate. "It''''s underexercise--underactivity--that''''s the problem. And we do know that sedentary people are fatter than active people."

Movement, exercise, or even fidgeting burns calories. Your level of activity may explain almost entirely why you have more or less body fat than your next-door neighbor, according to William J. Evans, Ph.D., director of the Noll Physiological Research Center at Pennsylvania State University in University Park. Researchers have learned that some people are natural-born fidgeters and movers, and those movers are almost always leaner than their calmer sisters, says Dr. Evans.

Whatever our natural tendencies, we can all increase our movement by adding more exercise. As soon as we burn more calories in activity than we consume in food, we shed fat: Once we''''ve burned the calories we eat in our daily meals (when we don''''t eat too many of them), we begin to tap the stored energy in our fat cells, too.

Exercise can also build muscle. That muscle tissue, once built, burns 30 to 50 more calories than fatty tissue. So, the more muscle you have, the higher your calorie burn. In fact, folks who exercise an hour a day use up about 8 percent more calories than the average couch potato--even when the exerciser is at rest.

Taking Steps toward Tummy Taming

The best news of all is that exercise can move you to the lowest rung of your set point--the weight your body tries to maintain. Round women don''''t turn wiry, but with exercise their curves can be sleek, taut and trimmer.

"Exercise greatly improves a person''''s ability to maintain weight loss, too," says Dr. Evans. "No other method has been shown to be more effective in weight maintenance."

If you''''re wondering how, here are some tips from experts.

Return to your childhood. First you have to pick a likely sport or activity. No clue? Well, what did you do as a kid? If you were a roller skater extraordinaire, try today''''s new, grown-up version: in-line skates. Some sports stores offer clinics where you can try out the skates with the guidance of a certified fitness instructor.

If tricycling was your childhood choice of sport, the increasingly popular pastime of mountain biking might be right up your valley, says Joan Price, certified fitness instructor, author of Yes, You CAN Get in Shape and owner-director of Unconventional Moves in Sebastopol, California. (See "The Calories You Burn Having Fun" on