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Perspectives |
1 From the Department of Radiological Sciences, University of California, Irvine Medical Center, Orange. Received August 1, 2002; accepted August 8. Address correspondence to the author, 18961 Castlegate Ln, Santa Ana, CA 92705 (e-mail: rmfriede@uci.edu)
Index terms: Economics, medical • Obesity • Perspectives
Obesity is a major medical and social problem in the United States. A simple clinical equation might define obesity as an imbalance between caloric intake and energy expenditure, but perhaps a more important equation is the effect of obesity on the individual that relates to his or her quality of life, social standing, and obesity-related medical diseases that produce substantial increases in morbidity and mortality.
Obesity today is considered to be a complex disorder primarily related to caloric intake and energy expenditure, as well as to the individual’s genetic phenotype, hormonal balance, cultural heritage, and the effect of the environment (1). It ranks with smoking and heavy drinking as major causes of chronic health conditions (2). The measure of obesity is calculated by means of the body mass index (BMI), which is determined by dividing the person’s weight in kilograms by the square of the person’s height in meters. A normal BMI ranges from 18.5 to 24.9. A BMI of 25.0–29.9 is considered overweight; 30.0–39.9, obese; and over 40.0, morbidly obese (1,2). There are two problems with the literal use of the BMI: (a) It uses weight rather than amount of fat, so that lean muscular individuals may be classified as obese; and (b) it does not differentiate between abdominal fat (android pattern) and hip and thigh fat (gynecoid pattern). The former reflects accumulation of fat around visceral organs and is more likely to be associated with medical complications, including dyslipidemia, hypertension, and glucose intolerance (1). Methods to assess the body distribution of fat, such as computed tomography and magnetic resonance imaging are too expensive to use routinely. Despite these limitations, however, the BMI is still considered the standard for determining overweight and obese categories.
What constitutes a desirable body mass and what is considered appealing to the public eye varies with culture and time. Wilbanks (3) points out that in the 17th and 18th centuries, obese girls were "sex objects," as is shown in paintings and sculptures of that period. Some religions (eg, Polynesian) venerate the obese person, and the Buddha is portrayed as morbidly obese. One of the first historical records about excesses in eating is related to St Gregory, Pope from 590 to 604, who conceived of the seven deadly sins, the fifth of which was gluttony (3). Supposedly, he was appalled by the excesses of the wealthy class in Rome when compared with the starvation and famine of the mass of the population.
After World War II, the concept of body image changed to that of the slim, often starved, appearance of models, and this concept has persisted so that today the public tends to have a negative opinion of obese individuals. Severe obesity can be a major social liability and a handicap when applying for a job. Many people, even physicians, believe that severe obesity is a character disorder rather than a disease, and few physicians make a concerted effort to treat obesity (3).
Between 1960 and 1980, there was only a minor increase in the overweight population. The major increase commenced in the 1980s and became endemic in the 1990s, with various authors (1,4,5) reporting a 60%–75% increase in obesity between 1991 and 2000. The prevalence of obesity, as defined by a BMI of over 30 as estimated by various authors, ranges from 15% to 27% in the United States, approximately one in five individuals in our population (1,2,4–6). When you reflect on how this affects population health and health care costs, it does seem strange that more funding and public attention has not been directed toward obesity. Much of the increase in obesity relates to an increasingly sedentary life fostered by television, desk jobs, increased use of automobiles, and movies, as well as the adoption of high-caloric and high-fat but inexpensive "fast foods" available on every corner of every city. Most of us like to eat, and we unbalance the simple equation that energy in must equal energy out to limit weight gain.
In a recent (2002) editorial, Yanovski and Yanovski (4) stated that 34% of adults in the United States have a BMI between 25 and 29.9 (overweight), and another 27% are obese with a BMI of over 30. Since 1980, obesity in adults has increased approximately 70%, and the number of overweight children and adolescents has doubled (4). Walker (7) estimated that 15% of adolescents are obese, and, if weight loss is not achieved in adolescence, only 5% will lose weight successfully in adulthood. Many overweight and obese individuals attempt to lose weight—often cyclically, with repeated weight loss followed by repeated weight gain—but only 20% of them restrict caloric intake and increase physical activity simultaneously (4). In fact, Borton and Teach (8) stated that 30% of adults are completely sedentary. Adding exercise to caloric restriction may not affect acute weight loss, but this appears to be a major component of maintaining long-term weight loss (4). Unfortunately, for the majority of individuals, acute weight loss is followed by a slow climb to prediet body weight. In addition to exercise, maintaining weight loss can be accomplished by the addition of weight-loss medication, but the safety of long-term (>2 years) use of drugs has not been established. For those who are morbidly obese, surgery is an option. Yanovski and Yanovski (4) believe that surgical treatments such as gastric bypass are appropriate for persons with a BMI of over 40 or for those with related medical conditions and a BMI of over 35.
Obesity ranks with smoking and chronic alcoholism as a major behavioral risk factor (2). Although substantial public expenditures are provided to help curb smoking and alcoholism, very few funds are directed toward helping curb obesity. Chronic conditions are major items in health care funding, but obesity, which contributes to many chronic diseases, receives little attention. When you consider that one in three Americans is overweight and one in five is obese (2,4), you can appreciate the magnitude of the problem. A BMI in the obese range has roughly the same association with chronic health conditions and increased health care as does 20 years of aging and is associated with increased mortality in several diseases, primarily coronary heart disease (9,10), hypertension, stroke, diabetes, and certain cancers (2,11). Obesity is also associated with an increased incidence of osteoarthritis, high cholesterol level, gallbladder disease, sleep apnea, and respiratory problems (9). The major increase in medical complications occurs in individuals who exceed their recommended BMI by more than 20%, usually a BMI of over 28 (1).
It is difficult to estimate the health care costs of obesity, but they are probably greater than those smoking or drinking (2). Sturm (2) calculated that obesity is associated with an average increase in inpatient and outpatient health care costs of $395 per person per year, while the increased cost for smoking is $230 per person per year and that for problem drinking is $150 per person per year (2). Borton and Teach (8) state that obesity is the second leading cause of preventable death in the United States. They also calculated that from 1960 to 1994, obesity increased by more than 50% (13.4% to 22.3%) (8).
Most observers consider obesity to be a complex multigenic disorder in which there is an interaction between genes and environment (12). Genetic factors probably play a role in obesity, but it is difficult to separate them from social factors. Different ethnic groups and cultures have different rates of obesity, but this may simply be related to the varying degree of preoccupation with being overweight in these cultures. Considerable work has been and is being performed in efforts to identify genes associated with obesity. Despite the difficulty of separating genetic influences in obesity from social and environmental factors, most observers agree that a genetic influence is important.
Stunkard et al (13) showed that there is a strong correlation between the BMI of people who had been adopted and that of their biologic parents and siblings but no correlation with the BMI of members of the adoptive family. The authors, in another study, showed that identical twins reared together or apart had a 70% correlation (both twins obese), which is much higher than that of fraternal twins (13). Twenty-five Mendelian disorders exhibiting obesity have been mapped. The numbers of genes, markers, and chromosomal regions associated or linked with human obesity phenotypes is now more than 250 (14). Although there is a general belief in the importance of the interaction between genes and environment, there has not been convincing evidence of a single genetic variant as having a primary association with body weight regulation (12), although the hormone leptin has been found to correlate with the BMI and, possibly, energy expenditure (7).
Weintraub (15) in 1992 showed the efficacy of combining medications with behavioral treatment in obesity (15). With this combination, weight loss could be maintained for as long as 3
years. Weintraub believes that obesity should be treated like any other chronic disease, with continuing medical care.
Medications approved for weight loss fall into two categories: those that decrease food intake by reducing appetite or increasing satiety and those that decrease nutrient absorption. Medications that decrease appetite are usually noradrenergic or serotonergic drugs, while orlistat is an example of a Food and Drug Administration–approved medication that reduces nutrient absorption. Serdula et al (16) estimated that $33 billion is spent annually for weight-loss products and services. In their survey, more than two-thirds of U.S. adults were trying to lose or maintain their weight, but only one-fifth of those trying to lose weight reported using a combination of fewer calories and engaging in 150 minutes per week or more of leisure-time physical activity, as recommended by the National Institutes of Health (9). Serdula et al (16) think that the increase in obesity in the United States is due to an increase in energy intake combined with a decline in physical activity brought about by societal changes, such as the availability of television, labor-saving devices, automobiles, video entertainment, and fast food restaurants.
The National Institutes of Health recommends that when weight loss is attempted, behavioral therapy alone should be instituted for 6 months and drugs should be added to the treatment plan in patients with a BMI of over 30 if behavioral therapy is unsuccessful or in patients with a BMI of over 27 who have related medical conditions (17). Once initiated, drug therapy should be maintained long term to reduce the rate of regaining of weight. However, the safety of weight loss medications used for more than 2 years has not been established. Many pharmaceutical companies are evaluating new drugs in clinical trials because of the huge potential market. Although there are many herbal preparations available, they are not recommended by the National Institutes of Health because of the design of the clinical trials and the lack of evidence for safety or efficacy (17).
Data on obesity were collected from 1991 through 2000 in each individual state by the Behavioral Risk Factor Surveillance System, with coordination by the Centers for Disease Control and Prevention (6). The total sample size was 182,444, and the median state sample size was 3,338. The data were obtained by means of telephone surveys of randomly selected persons aged 18 years and older. By using a BMI of over 30 as the definition of obesity, the prevalence of obesity increased in all states, confirming findings suggestive of a growing national epidemic of obesity. In 1991, the median percentage of the population in all states that was obese was 11.4%, while in 2000 it was 19.6%. This supported claims that one in five individuals is not merely overweight, but obese. In addition, since the answers were furnished as self-reports over the telephone, social pressures tend to cause individuals to underestimate their weight (6).
Former Surgeon General C. Everett Koop, MD, who launched Shape Up America!, stated that other than smoking, which he reported causes an estimated 500,000 deaths annually, obesity-related conditions are the second leading cause of death, resulting in about 300,000 lives lost each year (18). The authors of a Wall Street Journal article (19) criticized that statement and noted that there is no direct evidence that obesity is truly a disease. They quoted researchers from the University of North Carolina (Chapel Hill) and the U.S. government who found that the additional risk of death posed by excess weight lessens with age. The authors of the Wall Street Journal article reported that the pressure to designate obesity as a disease is encouraged by pharmaceutical companies trying to sell weight-loss drugs. Although there is no question that the effects of obesity are estimates and may be exaggerated, we must accept the fact that obesity leads to serious complications and has increased dramatically over the past decade. It has become a serious medical problem that must be addressed.
As yet, no one has found a satisfactory way to achieve long-term weight reduction that works on a population-wide basis. Efforts at voluntary weight loss have produced expenditures estimated at $30–$50 billion annually and ultimately are not very effective. In 1994, Kuczmarski et al (20) presented facts from the National Health and Nutrition Examination Survey (NHANES), where overweight was defined as a BMI of 27.8 or greater for men and 27.3 for women. For all race and ethnic groups in the United States combined, 31% of adult men and 35% of adult women were estimated to be overweight, with the largest percentage being in Mexican-American women and non-Hispanic black women (20).
Further data from the NHANES, published in 1998, show that the prevalence of obesity (BMI > 30) increased from 12% in 1991 to 17.9% in 1998 (21). Remember, this survey was conducted by means of random telephone calls, and, since individuals providing this information tend to underestimate their weight and overestimate their height, the true rates of obesity are likely to be underestimates.
Must and associates (22), using data from the Third NHANES, estimated that one in two adults in the United States is overweight or obese. They used the standard definition of a BMI of 30 or greater as obese, but they then classified that group into three subgroups: class 1, BMI of 30.0–34.9; class 2, BMI of 35.0–39.9; and class 3, BMI of 40.0 or higher. On the basis of that sample, approximately 63% of men and 55% of women aged 25 years or older in the United States were overweight or obese. Using data from the Third NHANES published by the National Heart, Lung, and Blood Institute in 1998 (9), Must and associates (22) correlated sociodemographic and morbidity factors, some of which are presented in Tables 1 and 2.
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Allison and associates (23), using a reference category of BMI in the range of 23–25, calculated how many individuals over the age of 18 years died in a given year (1991) due to obesity. They arrived at the number 280,000 in the general population, similar to the estimates of Koop (18), and 325,000 when one assumed a nonsmoking general population. The largest proportion of deaths occurred in persons with a BMI of at least 30, which represents about 40.5 million Americans, according to the results of the Third NHANES (23). Allison et al believe that with our increasing population and the continual increase in the percentage of that population that is obese or morbidly obese, the number dying of obesity-related disease will increase. Stevens et al (24) calculated that moderate obesity generally results in a 1–3-year reduction in life expectancy, depending on the age of the obese individual.
There will be considerable resistance to a declaration of obesity as a chronic medical disease, because substantial economic incentives are involved in the delivery of substances that increase weight. Fast foods and fast food restaurants are promoted by industry through advertising, which has a strong influence among young people despite the fact that a BMI of over 28 is associated with increased risk of morbidity and mortality.
Recently, U.S. News & World Report (25) commented on the more than 60% of American adults who were overweight, with approximately 27% of this group classified as obese. The authors of that article commented that obesity among adolescents has doubled to 13% since the early 1970s. The surgeon general has declared obesity to be a national epidemic, and the Centers for Disease Control and Prevention say it is fast replacing smoking as "public health enemy number one" (25). The financial costs, according to calculations in the U.S. News & World Report article, are staggering: some $117 billion annually in health care costs and lost wages (25). Some trial lawyers may now take on the fast food and snack industry, known collectively as the "big fat" (25). These lawyers claim that, overall, the food industry spends some $30 billion a year on advertising and uses manipulative strategies to market unhealthful products that, when consumed regularly, can lead to disease and death (25). Kelly Brownell, a Yale psychologist, notes that the entire federal budget for nutritional education equals one-fifth the advertising costs for Altoids mints (25). Brownell desires a "fat tax," a tax on fast food and snacks based on their propensity to contribute to obesity. Brownell believes that the money raised with such a tax could subsidize healthful foods and promote fitness education.
Although most individuals would like to see Congress rather than lawyers take action, if legislation does not occur various class action suits may arise, first against companies that misrepresent fat content and then regarding the issue of misleading advertising such as that for so-called energy health bars passed off as health food when they really are candy bars. For example, certain fast foods may contain more calories than are recommended by the government for an average adult to eat in a full day. At the time this Perspectives article was written, the August 5, 2002, edition of U.S. News & World Report (26) noted that a New York City man was suing four fast food chains, McDonald’s, Burger King, Wendy’s, and KFC, claiming that they provided deceptive nutritional information for their high-caloric high-fat foods, which he ate five times each week. The National Restaurant Association classifies this as a frivolous suit, but the plaintiff’s lawyer claims that the deceptive advertising affected his client’s health and the plaintiff is suing for costs.
Obesity today ranks as a major social and medical problem. The tremendous increase in the overweight and obese population over the past 20 years should alert our government and medical community to the need for public education and medical therapy. Obesity is preventable; theoretically, this should make it easier to treat than most medical disorders. Despite the many articles related to increased health risks with increased BMI, many of us unfortunately fall into the category of those who "live to eat" rather than "eat to live." It is accepted by most medical authorities that there are medically related diseases in the obese that increase morbidity and mortality and shorten overall life span. In addition, there are social consequences that tend to place individuals who are obese in the fringes of society.
Bottom line: The waistline of America is increasing rapidly, and this is unhealthy. More than 55% of Americans are overweight, and obesity, a BMI of over 30, is present in about one in five individuals. This may be an embarrassing and very personal topic that those of us who are obese resent. But if obesity, like smoking, is related to increasing morbidity and mortality, we must fight it. Remember, the major increase in obesity occurred over the past decade, and we have not yet experienced the increased mortality and increased health care costs this will bring as this population ages. Remember, obesity in adolescence is a problem, since adolescents who are obese rarely lose this weight as adults. Legitimate weight maintenance programs should be covered as a medical expense. Obesity should be considered a disease, and our medical profession—and our politicians—should insist that public health funds be directed toward publicity and prevention.
REFERENCES
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  R. C. Chandler, G. Srinivas, K. N. Chintapalli, W. H. Schwesinger, and S. R. Prasad Imaging in Bariatric Surgery: A Guide to Postsurgical Anatomy and Common Complications Am. J. Roentgenol., January 1, 2008; 190(1): 122 - 135. [Abstract] [Full Text] [PDF]
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