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Chapter Two Weight Loss: Our National Obsession In early adolescence, girls learn how important appearance is in defining social acceptability.  Attractiveness is both a necessary and a sufficient condition for girls' success.  This is an old, old problem.  Helen of Troy didn't launch a thousand ships because she was a hard worker.  Juliet wasn't loved for her math ability. -Mary Pipher, Reviving Ophelia Over the past hundred years, society has done a terrible disservice to girls and women by inextricably linking feminine beauty to a slender body.  This has given them the mistaken impression that to be loved, valued, successful, and attractive, they need to be slim.  Beginning as far back as the turn of the century, many women have responded to this pressure by dieting and exercising in hopes of attaining the "ideal shape." They believed (and many still do believe) that the mind could will the body to take on an entirely new form-even one that was totally unnatural.  They learned dieting "tricks" such as starving and purging.  But Mother Nature was (and is) a formidable opponent in the weight-loss game, one who triggers binges and slows the metabolism to effectively keep most body weight firmly in place.  Women have found themselves between a rock and a hard place-society compells them to be thin, but Mother Nature finds ways to keep them at their natural weight. Still, society won't let up.  In fact, as the years have rolled by, the "ideal shape," a concept widely promoted by the media, has become thinner and thinner.  (Miss Sweden of 1951 was 5'7" and 151 pounds; Miss Sweden of 1983 was 5'9" and 109 pounds.) Today it's practically impossible to achieve the dangerous levels of thinness glamorized in magazines, on television, or in the movies while maintaining good health.  Unfortunately, too many girls and young women are trying to do just that. This is not to say that all changes in diet or exercise habits are unhealthful or dangerous.  For some people, small changes in these areas can be wise and healthful strategies-- if they're done in moderation and if extra pounds are due to gobbling too many goodies or sitting in front of the TV too long.  But if dieting or exercising is taken to an extreme, or if the dieter is trying to sculpt an entirely new body shape that Mother Nature never intended, problems can arise.  Both mind and body may revolt-and the result is often the development of a full-blown eating disorder. How do I know if I really have a weight problem or I'm just trying to make my body look a certain way? To answer this question, we'll need to define four terms: overweight, overfat, obese, and Body Mass Index (BMI). Overweight simply means that you weigh at least 10 percent more than is recommended for your height, frame, and age, but that isn't a reliable sign that you've got a health problem.  Muscle tissue weighs more than fat, so if you are a body builder or an athlete or simply have a genetic predisposition to putting on muscle, being overweight may be perfectly healthy for you.  That's why looking at weight charts or hopping on the scale isn't the best way to determine whether you need to lose weight. Overfat is the presence of too much body fat, which can occur not only in overweight people but also in those of normal weight.  For example, even though she may look lean, a skinny model may actually be overfat if she doesn't exercise enough and has a low percentage of muscle mass.  Weighing yourself won't tell you if you've got too much body fat.  Your body fat percentage is a much more accurate indication of a possible health problem. Recommended body fat percentages are 20 to 30 percent for women and 12 to 20 percent for men. Be aware that a very low body fat percentage can be just as dangerous as one that's too high, since it suggests that the body is in a starvation state.  Women who dip much below 18 percent can develop a hormone imbalance that results in osteoporosis (the thinning of the bones) and the loss of menstruation (amenorrhea).  Some long-term anorexics end up with bones that are as thin and brittle as those of a seventy-year-old woman.  Kidney dysfunction and liver problems are also side effects of eating too little food for too long. The most accurate method of determining body fat percentage is hydrostatic (underwater) weighing, but it can also be determined by measuring a fold of skin with special calipers; passing a painless, low-energy electrical current through the body; measuring the amount of radioactive potassium that the body emits; or using infrared light.  Ask your doctor how and where you can get an accurate assessment of your body fat percentage. Obesity is defined by some experts as being more than 20 percent over the recommended weight for a person's height, frame, and age, but as you know, poundage alone isn't an accurate assessment of health.  Others define obesity as more than 20 percent body fat in men and more than 30 percent body fat in women.  A third definition, more accurate than the other two, involves the BMI, or Body Mass Index.   Your doctor or a clinician can calculate this for you-or you can figure it yourself. What makes one person more likely to develop a weight problem than another person? Any of the following factors can contribute to the likelihood that you will become obese. Heredity Being female Overfeeding during infancy, adolescence, or pregnancy Significant overeating for a long period of time Using food as a reward or to relieve stress or depression Being a first- or second-generation American Dieting About heredity-both of my parents are heavy.  Does that mean I'm going to be heavy too? Not necessarily, although the odds are good.  A child who has one obese parent stands a 40 percent chance of becoming obese.  The child of two obese parents, however, has an 80 percent chance.  The size and location of the fat deposits, bone size, metabolism, and other factors are all determined by heredity, so if your parents were large, you'll probably be large, too. Heavy people also tend to have less brown fat, a special kind of fatty tissue that helps to raise the body temperature slightly and burn off excess calories.  While a thin body may be able to burn off an extra load of calories quickly, an overweight body is often genetically programmed to be "thrifty," saving every last calorie.  We've all heard the complaint "She eats all day long and never gains any weight.  I eat one cookie and gain two pounds!" Brown fat may be at least part of the reason. You can't change your genetic legacy.  But rather than trying to become something or someone you were never intended to be, why not concentrate on becoming as healthy as possible, through good nutrition and moderate, regular exercise? Radiant good health is the most attractive thing that anyone can wear, while poor health, even on a "perfect" body, is anything but pretty. Why are females more likely to become obese? Females are genetically programmed to carry greater amounts of fat--for reproductive reasons, for insulation, and to provide a ready supply of calories for breast-feeding an infant.  Females are most likely to put on extra fatty tissue at certain well-defined times in their lives--during infancy (when many fat cells are formed), during puberty (when body fat must reach approximately 20 percent for menstruation to begin), and during pregnancy (when fatty tissue is added so there will be sufficient calories for milk production once the baby arrives).  But it also appears that fat generates fat--that is, the more fat cells a person has, the more efficient the body becomes at producing and storing them.  So females (who are genetically programmed to carry more fat than males) tend to be especially good at both generating and holding on to fat deposits. Males, on the other hand, have greater amounts of lean body tissue (muscle), which is more metabolically active than fatty tissue (meaning that it burns more calories, even in the resting state).  As a result, the average man has a higher metabolic rate and burns off calories faster than the average woman.  The upshot of all of this is that women are more likely to become obese than men, a fact that becomes even more apparent as we age.  Among older people (age sixty-five and above), one half of the women are obese compared with one third of the men. How can overfeeding during infancy contribute to obesity? The majority of fat cells are formed during the first two years of life.  Overfeeding during this crucial time period can cause an abnormally high number of fat cells to be created.  Once laid down, fat cells function by swelling up during times when food is plentiful, then shrinking during times of famine as the fatty acids are withdrawn and used for fuel.  But even when food intake has been restricted for a long period of time, these fat cells never disappear.  They simply lie dormant and wait for their chance to inflate again.  An infant who is overfed, then, creates an excess number of fat cells that she's stuck with for the rest of her life. To make matter worse, greater amounts of fat cells inspire greater amounts of hunger.  So the person carrying a large number of fat cells is actually fighting a double battle when she tries to lose weight: she has fat cells that won't go away, plus abnormal hunger.  One study found that the number of fat cells a person has is a good predictor of how successful she will be at losing weight. How does overfeeding during adolescence or pregnancy contribute to the likelihood of obesity? During adolescence and pregnancy, a girl or woman will gain body fat even faster than she gains lean tissue, so overfeeding can have disastrous consequences.  Many will find that the weight they gain during these periods stays with them for life.  If she can get through these periods without gaining an excessive amount of weight, her chances of becoming obese will be markedly reduced.  Therefore, good nutrition and moderate, regular exercise during adolescence and pregnancy can be critical for the prevention of obesity. Does overeating over a long period of time make new fat cells appear? At one time, experts believed that once the fat cells had been laid down (around the age of two), they simply swelled and shrank in response to the food supply.  Now many researchers in the field believe that new fat cells can be created in the presence of continual overfeeding.  This makes sense when you consider that some morbidly obese people tip the scales at 800 or 1,000 pounds.      Excerpted from If You Think You Have an Eating Disorder by John Barnhill, Nadine Taylor All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.