Cover image for The skinny on fat
Title:
The skinny on fat
Author:
Vogel, Shawna.
Personal Author:
Publication Information:
New York : W.H. Freeman, [1999]

©1999
Physical Description:
viii, 264 pages ; 20 cm
Language:
English
Subject Term:

ISBN:
9780716730910
Format :
Book

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Status
Central Library RC628 .V64 1999 Adult Non-Fiction Central Closed Stacks
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Summary

Summary

As a society, we are more health conscious than ever before, yet one in four Americans is considered obese. The confusing bombardment of information we receive daily about diet and exercise has done little to answer the perennial question -- "What's the best way to lose weight?"Separating fact from fiction, The Skinny on Fat examines weight gain and health from a scientific point of view, describing what recent research tells us about how our bodies work, why we gain weight, and whether we should diet at all. Some of the topics it covers include: -- The weight control drugs of yesterday, today, and tomorrow-- Diet and exercise-- The molecular and genetic basis of weight-- Is obesity a disease?-- Getting thin the healthy way-- The future of weight controlNot a miracle program for weight loss, The Skinny on Fat is a revealing look at how the scientific view of obesity has resulted in a new definition of fat -- one that contains more biology and less guilt. It is essential reading for anyone, regardless of weight, who is interested in living a healthier life.


Excerpts

Excerpts

Chapter One All in the Family ARE WE GENETICALLY PROGRAMMED TO BE FAT? John Rossi had worked at the Kragen Auto Parts store in Berkeley, California for ten consecutive years, first as a clerk and then as a manager. He was a model employee, missing only three days in all that time and regularly working 50- to 60-hour weeks. So it was something of a surprise when one July day, Rossi's manager told him not to come into work anymore.     A spokesman for the store later said that Rossi was fired for poor job performance. But the only reason Rossi could see for his dismissal was the fact that he was fat. A high school football star, Rossi had struggled with obesity throughout his adult life. He had seen his weight soar to 275 pounds by the age of 21, when he first started working at Kragen. And over the next decade he tried everything, from fasting to hypnosis. He even wired his jaws shut. But in spite of his efforts, Rossi's weight continued to climb. On the day he was fired he weighed about 400 pounds.     The weight encumbers Rossi. It is difficult for him to sit, stand, and walk. But it never affected his job performance, as shown by the company's own evaluations along with laudatory letters from customers. Therefore Rossi did what any self-respecting person would do under the circumstances. He sued.     His case, brought under the California Fair Employment and Housing Act, became a landmark in our societal definition of what it means to be fat, though it was by no means the first such suit to test the way the courts treat the overweight. Under the same law, a Santa Cruz woman named Toni Cassista filed a discrimination suit against Community Foods, Inc., a health food store that refused to hire her because of her severe obesity.     Cassista's case did not go well. In 1993, the California supreme court ruled against her. The court decided that employment discrimination against an obese person wasn't illegal unless it could be proved that the person's weight was the result of a physiological disorder. In other words, the courts treated Cassista's obesity as a condition that she could change if only she set her mind to it.     That ruling was in line with popular assumptions about obesity--that it is caused by a lack of willpower; that people who become obese simply need to push themselves away from the table sooner. And if that were truly the case, it would have been very much in agreement with the way disability law is intended to work. In most states it is perfectly legal to fire someone if you think they are ugly or smell bad and you don't want to put up with them any longer. Only if they have a physical or mental impairment--a condition beyond their control--are they protected by the Americans with Disabilities Act and similar laws in many states.     Cassista, though she clearly felt she was being discriminated against because of an involuntary condition, never saw her weight as a disability. She therefore felt that it would be unconscionable to claim such a thing in court. The result of her principled stance was that her lawyer never called on an expert witness to explain the medical basis of her weight, and Cassista lost the case.     Lynette Labinger was loath to make the same mistake. Two days after the Cassista decision came down, Labinger, an attorney, was scheduled to argue a similar case--the appeal of Bonnie Cook. Cook sued the state of Rhode Island for refusing to hire her at a home for retarded people. She had worked at the home before, from 1978 to 1980 and again from 1981 to 1986. Both times she had left voluntarily, and with a clean employment record. But in 1988, when she applied for the job a third time, she weighed more than 320 pounds--significantly more than she had during her prior years of employment at the home. The physician responsible for approving her application rejected it, claiming that her weight compromised her ability to evacuate patients in an emergency and increased her risk for heart disease, thereby increasing the likelihood that she would need worker's compensation.     The fact that the Cassista decision was negative sounded an ominous warning for Cook and certainly would have influenced Labinger's tactics had it come a little earlier. As it was, Labinger didn't have a lot of time to dwell on the implications of the ruling. "I was scrambling around, reading the decision, trying to figure out how I was going to deal with it in oral argument," she says.     Fortunately, she had done her homework. As part of the preparation for the jury trial she lined up Arthur Frank, Medical Director for the Obesity Management Program at the George Washington University School of Medicine in Washington, D.C., as an expert medical witness. Trained in biochemistry but with a psychological bent, Frank is an individual of overwhelming humanity. He gracefully straddles the awkward boundary between the biochemical underpinnings of obesity and the very human task of coping with it daily.     He began his testimony by dispelling the myth that people have a lot of say about their weight. Using himself as an example, he told the jury that he was "a random eater. I don't pay any attention to what I eat and over the last twenty years my weight hasn't changed at all." Then, to paint a mental picture, he explained that the number of calories he would have to eat in order to put on an extra pound a year amounted to no more than a few peanuts a day. Knowing that to be the case, he said, any reasonable person would have to conclude that our bodies take care of our weight without any conscious help.     "Nature does not permit body weight to fluctuate randomly in other mammals," Frank wrote in a commentary published around the time that he appeared in court. "It is inconceivable that humans would have a randomly unstable weight. Even obese people are usually weight stable, albeit at an inappropriate level. We weigh what we are supposed to weigh, and the regulatory systems defend that weight with remarkable physiologic tenacity." Although Frank made it clear in this commentary that people can at times override these controls by deliberate effort or because their emotional climate changes, he wrote, "There is no reason to believe that patients' behavior causes this disease."     Frank wasn't saying that people couldn't gain weight by overeating--just that it is difficult to fatten people up unless their bodies are susceptible to it. He also wasn't saying that obesity couldn't be an outgrowth of a psychological trauma like childhood abuse. But in his eyes, psychology has little to do with causing people to overeat or to be fat. Rather, he says, it plays a role in their ability to cope with gaining weight and their comfort in sustaining a heavy weight once they've reached it.     Frank's straightforward view of obesity sliced through the stereotypes. People so often blame emotions for excess weight. They think there is something psychologically wrong with people that causes them to be fat. As a result, fat people have guilt heaped on them by society, in addition to the physical burden they themselves carry. But in Frank's comments to the jury, he maintained that there were clear biochemical reasons why people crave something sweet at a certain hour of the day or a bowlful of pasta when they are feeling stressed, and the reasons have nothing whatsoever to do with will power.     Frank took the wind out of the sails of anyone in the courtroom who assumed that if obese people would just eat better and exercise more they wouldn't look the way they do. His testimony meant that for someone like Cook, the requirement that she lose weight to get a job was the equivalent of a sentence to starve herself. She might be able to do it, but the biological drive to eat would linger as long as the weight was gone.     The jury took Frank's words to heart. Cook won her case and its subsequent appeal, setting a precedent in the federal court system. Two years later, John Rossi's jury also granted him a victory. The verdict established a separate precedent in the California courts, but it was the size of the award that made this case a landmark. Rossi's jury granted him the sum of $1,035,652 for lost compensation and emotional distress.     When Rossi heard the verdict in the courtroom, he finally let out his tears. After a four-year battle of legal depositions, settlement meetings, and testimony, he was finally the hero of the story instead of the victim. The million-dollar verdict put the final nail in the coffin of obesity discrimination lawsuits. And just as in the Cook case, what had convinced Rossi's jury was the science.     The key to the verdict, according to Rossi's lawyer, Barbara Lawless, was testimony by an expert medical witness that obesity is 80 percent genetic. Actually, the 80 percent figure is at the high end of the range usually given by experts in the genetics of obesity. Most researchers' estimates hover around 50 percent. But there is an overwhelming store of evidence pointing to the fact that weight is at least 5 percent and in some cases as much as 90 percent inherited. Where the courts have based their decisions on this scientific research, weight discrimination suits have triumphed.     Yet the legal travails of Rossi and Cook bring up an important point. The courts protected them from discrimination because they could make a clear case that their morbid obesity was an immutable condition. In doing so, however, the courts have drawn a sharp cutoff where in biology only a blurry boundary exists.     There is no magic line between being morbidly obese (which is defined as body weight more than 100 percent above the norm) and being merely overweight. Genetic research shows that they are just different aspects of a continuum that extends all the way down the weight scale from the minority of people who weigh upwards of 300 pounds to the vast majority who would just like to lose the spare tire they have gained since high school. All these people simply have a greater or lesser genetic susceptibility to gaining weight.     That's where things get confusing. Susceptibility? The word doesn't fit neatly into what we know about nature or nurture. It doesn't spell out a clear path for what people should do to lose weight. And yet, the genetic roots of this susceptibility are key to the rise in weight in this country. They dictate the extent to which any of us is destined to cling to that extra 20 pounds. They explain why two people can eat exactly the same amount and only one of them will get fat. As a result, genetics has taken on great importance for scientists trying to understand why people get fat. Inheriting Fat For over 20 years, families of French descent living within 50 miles of Quebec city have been voluntarily subjecting themselves to a battery of tests in order to help researchers understand how genes affect our weight. Paul-André Sauvageau, a retired civil engineer, and his family were among the first to join the Quebec Family Study. In 1979, Sauvageau took his wife, his 12-year-old son, and 10-year-old daughter to the Physical Activity Sciences Laboratory at Laval University in Ste-Foy. He was 47 at the time and an avid skier His wife, a dietitian, was ten years younger     Like Olympic decathloners, the family members took turns at half a dozen testing stations. They skipped their usual breakfast so that the technicians could measure their energy use in the fasting state and then again after they ate. They rode a stationary bicycle while doctors and technicians kept an eye on their heartbeats and other vital signs. They gave blood for what seemed to Sauvageau like a very long time. They strapped on weights and were plunged into the underwater weighing tank.     Sauvageau's wife didn't enjoy that test much. Nor did his sister-in-law, who also went to the lab along with three of Sauvageau's brothers-in-law and their children. But the extended family went back in 1991 and did the tests over again for phase 2 of the study, which looked at a subset of the original families. The Quebec Family Study data set now extends from 1978 to the present, and both because of this length and because of the thoroughness of the testing, it constitutes one of the best scientific resources on the genetics of health.     The study is the brainchild of a soft-spoken and highly regarded geneticist at Laval named Claude Bouchard. From the beginning Bouchard's plan was to look at the effect of genetic and nongenetic factors on body composition, on the response to exercise, on muscular strength, and on standard blood measurements, like pressure, cholesterol and fat content. But over the years the obesity component of the study has become by far the most prominent, perhaps because in the last two decades the weights of Canadians have increased just as quickly as those of Americans. A third of the populations of both countries are now obese. "Yeah," Bouchard says with a wry smile, "we share so many things."     Of course, finding the genetic component of obesity is slightly different from saying that it is something you get from your parents. Things like eating habits and attitudes toward food can be passed down simply because family members eat, sleep, and breathe under the same roof, which is why for many years it was difficult to say just how strong a role genes play in our eating behavior     But studies during the mid-1980s of identical twins helped tease apart the roles played in obesity by family environment and genes. Nowadays, nearly everyone is familiar with the stories of twins who have been separated for decades and then, when they finally reunite, can't help noticing an extraordinary number of similarities in the way they do everything from zip their pants to choose careers. This phenomenon also applies to BMI, or body mass index, a measure of weight in kilograms relative to height in meters (see the chart on the following page). Studies comparing identical twins reared apart with twins reared together show that biology is a much stronger influence on weight than family environment. The best estimates from twin studies say that between 40 and 70 percent of our BMI is determined by our genes.     In recent years, Bouchard's group has used their extensive data set to build on the estimates and show that not only BMI but a broad range of weight traits are hereditary. Bouchard and his colleagues have amassed information on body fat, on insulin metabolism, on fat within the bloodstream, on resting metabolic rate. They have done CT scans to measure visceral fat--fat that is located around internal organs like the heart, liver, or intestines. And they have collected cell lines for each family member, providing them access to each individual's DNA.     They have shown that one of the most important aspects of weight maintenance, our resting metabolic rate, or how much energy we burn when we aren't being active, is largely determined by our genes. Resting metabolism accounts for about 70 percent of the energy, or food, we burn in a given day. And studies by Bouchard's group as well as others suggest that 40 to 80 percent of the variance in this resting rate is inherited.     That doesn't necessarily mean that our DNA dictates whether we are one of those people who juggle sixteen projects simultaneously or among those who live by the tortoise's decree: slow and steady wins the race. People assume that metabolism is the key to how much vigor people have. But Bouchard's group has shown that genes exert only a small influence on how much general activity we do in a day. That means not just exercise but all kinds of activities. The researchers attribute only about 29 percent of the variation in this trait to genes. While active parents do indeed give rise to active children, it is mostly because they socialize their children to be that way.     There is also a genetic component to whether you will get a swag of loose flesh on your upper arm as you age or whether your ankles will stay sleek in spite of a bulging middle. In other words, genes affect not only whether you are fat but also where you are fat. Whether you have the shape of an apple or a pear has important consequences for how detrimental the extra weight you're carrying is to your health. Fat around our bellies is associated with a greater risk of diabetes, heart disease and hypertension, whereas hip and thigh fat is relatively benign. It may be easier to hide a bulging middle under a baggy sweater, but for health reasons a pear shape is good, an apple shape is bad. Heredity accounts for as much as 40 percent of the variance in the distribution of fat.     To a lesser extent, genes also influence how much fat is stored when we eat excess food. Overindulge, and your genes will show you whether you are one of those people who turn excess food into fat very efficiently or if you are a relative failure at fatmaking. Genes also determine how effective an exercise program will be in helping you lose weight. Dedicate yourself to daily exercise, and your genes will decide whether your commitment will lead to massive weight loss or a paltry few pounds.     There is also a genetic component to the kinds of food we decide to eat. Many people have already caught on to their own food preferences. They know they will pass up a bowl of candy for a juicy steak any day. Research has shown that steak lovers tend to beget steak lovers; roughly 10 to 20 percent of food selection is under genetic control.     Perhaps none of this is surprising. When we grow up we end up looking and acting a lot like our parents. It doesn't take a genius to realize that weight problems run in families. The apple doesn't fall far from the tree. But most of us also carry the notion that socialization has a large role in familial similarity. Your mother may have made an extraordinary plate of spaghetti in her day, and it's easy to assume that your current love of pasta is the result of that culinary tradition.     Many of us also feel that we have a large measure of choice as to whether we follow our parents' patterns. So it is interesting to learn to what extent not only our looks but our habits are hard-wired. Perhaps your mother spent so much time perfecting her spaghetti recipe because somewhere deep within her DNA was a carbohydrate-craving gene.     The fact that genes influence weight, however, doesn't mean that they are entirely to blame for the expansion of our nation's waistlines. The unspoken message in all these genetic percentages is that they are just that--percentages. Fractions. Our weight isn't 100 percent inherited. Indeed, a great deal of cultural evidence indicates that weight is partly the product of environment, a term researchers use to mean things like the food choices that are available, as well as how sedentary people are or how often they eat out.     Jose Caro, an obesity specialist at Lilly Research Labs in Indianapolis, once illustrated the impact of environment by describing his impressions from a trip to Beijing. "It's incredible what you see," he said. "The adult Chinese are elegant looking, thin. They eat rice and they ride bicycles. They are allowed to have only one child, and almost 100 percent of the children are obese. So you see you have a very weird situation where you have the overlap at the same time of a lean environment and an obese environment. The parents believe that what they were doing was bad and they were suffering and now they want to compensate and give more to their only child. So they take them to McDonalds. They don't allow their child to ride the bicycle; they buy electric motors. And you see these genes haven't changed." While the genetic heritage of these children remains the same, the environment in which they are reared allows for an alarming increase in obesity.     Caro's Chinese example may be anecdotal, but sudden leaps in the rate of obesity are common whenever people go from one food environment to another. Charles Rotimi, an obesity researcher at the Loyola University Medical Center, studied this phenomenon in his adopted town of Chicago. He found that when men and women from his former homeland, Nigeria, as well as Cameroon, emigrate to the land of the deep-dish pizza, their obesity rates skyrocket.     The average rural African Rotimi looked at had a body mass index of about 21, which means that a 6-foot man weighed about 155 pounds. By contrast, the average African who had moved to Chicago had a BMI of 30, which translates into a weight of 220 pounds for a man of the same height. African émigrés in the Caribbean and in Manchester, England, fell between these two extremes. "Basically it was just a very steep gradient from rural Africa through the Caribbean islands to Chicago," says Rotimi. "The assumption here, of course, is that these are populations of similar heritage in vastly different environments."     Rotimi has also found a lesser but still significant jump in the obesity rates when Nigerians move from rural areas to African cities. "The urban poor in Nigeria, which is the majority of the population, are struggling to meet daily nutritional requirements," he says. "But even within these sub-Saharan countries, if you look at the urban elite, they have this problem of obesity."     In the affluent West, the problem is even more severe and has grown worse over the last decade. The incidence of obesity in the United States had held steady at about 14 percent of the population since 1960, when the government began its National Health and Nutrition Examination Surveys. Then, between 1981 and 1991, it shot up to a quarter of Americans. This is on top of the gradual rise in the prevalence of obesity that has taken place over the last century. Both these increases have occurred far too quickly to be attributed to a change in our population's genetic makeup.     What's happening is that our existing genes are conspiring with our evolving environment to make us fat. "You start with some people who are more at risk," explains University of Pennsylvania geneticist Arlen Price, "and you make high-fat diets available to everyone and everyone gains weight and some people in particular really gain a lot. So you can actually see the gene-environment interactions changing in real time over the last century."     America's rising rate of obesity has been accompanied by shifts in who is affected. Twenty to thirty years ago it was more the norm for a prosperous person to be overweight--a "fat cat." The prevalence of obesity was substantially higher in upper-income groups than it is today. Now being overweight is no longer a status symbol. In addition, the better educated you are and the higher your income, the less likely you are to be sedentary, a radical shift in behavior within the population. In contrast with the time when vigorous activity was generally associated with lower socioeconomic status--literally the working class--physical activity has now become a luxury. Yet the fact that wealthy, educated groups have managed to control obesity indicates how strong an influence lifestyle can be.     Genes may not be everything, but compared to the tangled social fabric of fast-food meals, cities with no walking paths, and the American love affair with cars, genes are something scientists can locate, identify and isolate for careful scrutiny. And in the pursuit of obesity's genetic roots, what is ultimately important is not the percentage of body shape or metabolic rate that we inherit, but what specific genes affect weight and what variations in them cause weight to balloon. For while genes may not be wholly responsible for the way we look, they can have an enormous impact on some people. In the cutthroat arena of body consciousness, just where you fit on the continuum of nature versus nurture is critically important. (Continues...) Copyright © 1999 Shawna Vogel. All rights reserved.

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