by Morgan Downey, J.D.

In many segments of society, obesity is considered to be the result of an individual's failure to exercise self-control over patterns of physical activity and eating. Major medical and scientific authorities, basing their understanding of obesity on scientific evidence, regard the condition as a disease entity. Their categorization is resisted by significant elements of the health care system, namely, payors. Despite resistance, it is expected that broad acceptance by the public and health care payors that obesity is a disease in its own right will follow the scientific and medical consensus regarding this. This article summarizes the current state of affairs, principally in the United States, with regard to the recognition of obesity as a disease entity.

In most standard medical dictionaries obesity is defined as excess or abnormal adipose or fat tissue. For example, Stedman's Medical Dictionary (26^th edition, 1995) defines obesity as, "an abnormal increase in fat in the subcutaneous connective tissues." In many, but not all, epidemiological and clinical studies body mass index (BMI) has emerged as the preferred measure of a person's excess adipose tissue. BMI is defined as weight in kilograms divided by height in meters squared. The National Institutes of Health (NIH) and the World Health Organization (WHO) have used a BMI cutoff of > 30 to define obesity. That definition of obesity will be used in this article.

At first glance, it might appear obvious that obesity would be considered a disease. In the medical literature, "disease", "defect", "illness", "condition" and "syndrome" all have similar meanings and are often used interchangeably. The term "disorder" is usually defined as a derangement or abnormality of function, a morbid physical or mental state; the term is virtually synonymous with "disease" and "illness" and is frequently used in connection with obesity. A typical definition of disease can be found in Stedman's Medical Dictionary: [1]

Disease 1. An interruption, cessation, or disorder of body functions, systems, or organs. Syn. Illness, morbus, sickness. 2. A morbid entity characterized usually be at least two of these criteria: recognized etiologic agent(s), identifiable group of signs and symptoms, or consistent anatomical alterations. 3. Literally, dis-ease, the opposite of ease, when something is wrong with a bodily function.

In the second definition given above, obesity clearly meets all 3 criteria, not just 2. Regarding etiologic factors, the NIH states that "Obesity is a complex multifactorial chronic disease that develops from an interaction of genotype and the environment. Our understanding of how and why obesity develops is incomplete, but involves the integration of social, behavioral, cultural, physiological, metabolic and genetic factors." [2] The signs and symptoms of obesity include an excess accumulation of adipose tissue and are likely to include insulin resistance, increased glucose, elevated cholesterol and triglyceride levels, decreased levels of high-density lipoprotein and norepinephrine, and alterations in the activity of the sympathetic and parasympathetic nervous system. As for consistent anatomical alterations, obesity is marked by an increase in the size or number, or both, of fat cells distributed throughout the body.

Agencies of the US government, WHO and authoritative medical and scientific sources have recognized that obesity is as a disease entity and characterized it as such in their publications. For example, WHO publishes the International Classification of Diseases, 9^th Revision Clinical Modification (ICD-9-CM), which is the definitive compilation of diseases. In the United States, the Public Health Service (PHS) and the Health Care Financing Administration (HCFA), which administers the Medicare and Medicaid program, participate in developing the ICD classifications. ICD-9-CM lists "Obesity and other hyperalimentation" as No. 278 in the "Endocrine, Nutritional, Metabolic and Immunity Disorders" section. [3] The ICD-9-CM is recommended for use in all clinical settings but is required for reporting diagnoses and diseases to all PHS and HCFA programs. Obesity is also listed in other compilations of diseases and disorders and in medical encyclopedias (for example, see Appendix 1).

In 1995 the Institute of Medicine at the National Academy of Sciences published a report titled, Weighing the Options which states, " These figures [regarding the prevalence of obesity] point to the fact that obesity is one of the most pervasive public health problems in this country, a complex, multifactorial disease of appetite regulation and energy metabolism involving genetics, physiology, biochemistry, and the neurosciences, as well as environmental, psychological, and cultural factors. " [4] WHO declared in 1997 that, "Obesity is a chronic disease, prevalent in both developed and developing countries, and affecting children as well as adults.[5] The US Food and Drug Administration (FDA) recently noted in its final rules under the Dietary Supplements Health and Education Act of 1994 (Public Law 103-417), that "obesity is a disease." [6] (According to the FDA, a person's being overweight but less than obese refers not to a disease but to the structure and function of the body.) [6]

The Federal Trade Commission, which regulates commercial weight-loss practices organized by the Partnership for Healthy Weight Management, a partnership comprised of representatives from academia, government, commercial organizations, and advocacy groups (for a full list of members see Appendix 2). Members of the Partnership agreed to "Voluntary Guidelines for Providers of Weight Loss Products or Services," which declares that "Obesity is a serious, chronic disease that is known to reduce life span, increase disability and lead to many serious illnesses including diabetes, heart disease, and stroke."[7] The guidelines were established to "promote sound guidance to the general public on strategies for achieving and maintaining a healthy weight." [7]

Moreover, the Social Security Administration (SSA) has issued guidance on the evaluation of disability claims involving obesity, declaring that "Obesity is a complex, chronic disease characterized by excessive accumulation of body fat...[and] is generally the result of a combination of factors (e.g. genetic, environmental, and behavioral)." [8] The guidance then notes, "In one sense, the cause of obesity is simply that the energy (food) taken in exceeds the energy expended by the individual's body. However, the influences on intake, the influences on expenditure, the metabolic process in between, and the overall genetic controls are complex and not well understood." [8] According to the SSA, persons with obesity alone or in combination with other conditions may quality for disability benefits.

The American Medical Association (AMA) has taken the position that "Our AMA will urge physicians as well as managed care organizations and other third-party payors to recognize obesity as a complex disorder involving appetite regulation and energy metabolism that is associated with a variety of co-morbid conditions." [9] Dr. Robert H. Eckel, vice chairperson of the Nutrition Committee of the American Heart Association has declared, "Obesity itself has become a life-long disease, not a cosmetic issue, nor a moral judgement -- and it is becoming a dangerous epidemic."[10] His statement followed the AHA's earlier attention to obesity as a risk factor for heart disease.

As noted earlier, despite the weight of evidence that medical, scientific, and governmental authorities recognize obesity as a disease, the acceptance of this classification is slow to penetrate a significant component of the health care industry - payors.

HCFA, the US government agency responsible for administering the Medicare and Medicaid programs has 2 policies relating to Medicare coverage of obesity. (Medicare was established by the federal government primarily for persons over the age of 65 but also covers individuals who are medically disabled.) Coverage of obesity is explained in the Medicare Coverage Issues Manual, one section of which (¶35-26) declares that "Obesity itself cannot be considered an illness. The immediate cause is a caloric intake which is persistently higher than caloric output. Program payment may not be made for treatment of obesity alone since this treatment is not reasonable and necessary for the diagnosis or treatment of an illness or injury." [11] But the Coverage Issues Manual recognizes that "obesity can aggravate a number of cardiac and respiratory diseases as well as diabetes and hypertension. Therefore, services in connection with the treatment of obesity are covered services when such services are an integral and necessary part of a course of treatment for one of these illnesses." [11] Medicare, will, however, cover gastric bypass surgery for patients "with extreme obesity." In such cases, as is noted in another section (¶35-40), Medicare covers services if the suregery "is medically appropriate and the surgery is necessary to correct an illness which caused the obesity or was aggravated by the obesity." [12]. Thus, as these quotations show, the Medicare policy on obesity is that (1) it is not an illness and (2) because it causes or aggravates other illnesses, treatment will be covered to correct it when those other conditions are present.

HCFA also administers Medicaid, the federal-state health insurance program for qualified individuals whose income is below a certain prespecified level. Medicaid programs may pay for certain outpatient pharmaceutical products. Under Title 19 of the Social Security Act (1935) (42 USC 301 et seq), a state choosing to include drugs for its Medicaid recipients must include all FDA-approved drugs except those for anorexia, weight loss or weight gain, fertility or smoking cessation, among others. [13] Nine states include antiobesity pharmaceutical products; 29 states specifically exclude antiobesity products.

With regard to private health insurance coverage, the picture is not much better. Most health insurers do not pay for any obesity treatments. Obesity medications are excluded by >80% of the employers who provide insurance coverage to their employees.

Since an Internal Revenue Service (IRS) Revenue Ruling in 1979, [14], the IRS has denied a medical deduction to taxpayers for the unreimbursed out-of-pocket costs of weight-loss treatments. The official IRS advice to taxpayers for the 1999 tax year was, "You cannot include the cost of a weight loss program for your general health even if your doctor prescribes the program." [15] In 1999, however, the American Obesity Association and 9 organizations ¹³ filed a petition to the IRS seeking a revision in its policy regarding deductibility of weight-loss treatments. (For the 9 organizations that joined this filing, see Appendix 3). Reacting to the IRS response, these organizations made an extensive filing in March, 2000, providing evidence that obesity is recognized to be a disease. For tax returns for the year 2000, the IRS dramatically revised its advice to taxpayers. Its new advice reads " You cannot include the cost of a weight-loss program in the medical expenses if the purpose of the weight control is to maintain your general good health. But you can include the cost of a weight-loss program undertaken at a physician's direction to treat an existing disease (such as heart disease)." [16]

Several barriers to the development of a more widely accepted understanding of obesity as a disease entity still exist. Foremost, is the view that a person's weight is determined by his or her will power and is thus exclusively a matter of personal responsibility. In this view the person who is overweight or obeseis blamed for his or her condition and there is a judgement that support or assistance, which might be otherwise forthcoming, should be withheld. On the other hand, many persons have difficulty with the idea of disease as a condition that may be self-inflicted. In their view, disease is something that one acquires, like an infection or is predisposed to, as a result of genetics -- not something over which a person has control. In this model of disease, the individual is a victim and blameless. These w complementary models may both come into play to determine the manner in which different types of illnesses or morbid conditions are regarded, and on closer examination it appears that the position that society takes regarding different illnesses is hardly consistent. For example, hypertension, hypercholesterolemia, and non-insulin dependent diabete mellitus (type 2 diabetes), may be as subject to some amelioration by changes in personal behavior, as is obesity, yet they are still considered diseases. Human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) and other sexually transmitted diseases may be brought about by risk-taking personal behavior to an even greater extent than the condition of obesity may be brought about; but they, too, are still regarded as diseases. Lung cancer may be preventable in many cases by lifestyle changes (e.g. smoking cessation), but it is regarded as a disease nonetheless. Injuries sustained by athletes such as mountain bikers or boxers, or injuries sustained by bungee jumpers or automobile drivers who drive without seat belts or while intoxicated, are all termed "accidents"; yet health insurance still covers the medical and hospital costs.

Another putative reason for resisting the classification of obesity as a disease may be found in the argument, sometimes made, that holds the following: that everyone carries adipose tissue, that the definition of what constitutes "excess" adipose tissue is subject to social and cultural norms, and that not everyone who carries excess adipose tissue is, in a reasonable sense, "sick." However, research has provided clear evidence about the relationship of weight to health. According to the National Task Force on the Prevention and Treatment of Obesity, "the data linking overweight and obesity to adverse health outcomes are well established and incontrovertible." [17]

Finally, some payors maintain that the lack of a highly effective treatment for obesity and the high rate of relapse after various interventions have been tried are reasons not to regard obesity as a disease. But surely this approach is misplaced. The presence or absence of an effective treatment cannot be the criterion by which to determine whether a disease exists.

The approach, noted above, that the HCFA and the IRS have taken regarding obesity is particularly troubling. It involves 3 steps: (1) deny that obesity is a disease or illness, (2) recognize that obesity causes or aggravates numerous health conditions, and (3) allow coverage (or deduction) only when the patient has a particular condition caused by obesity. The flaws in this approach are evident. It is worth noting neither the IRS deduction for smoking-cessation products and services nor the deduction for alcohol rehabilitation is dependent on whether the tax payer claiming the deduction(s) has lung cancer or liver disease. Neither hypertension nor elevated cholesterol levels are treated only after an individual has had a first heart attack or stroke, nor do physicians wait to treat HIV/AIDs until the patient has pneumonia. Given the documented increase in obesity in both the pediatric and adult populations in the United States and and given the recognition of obesity as a major health problem in the United States, including its inclusion this year by the PHS as one of the nation's 10 leading health indicators, the approach to obesity that the HCFA and the IRS have taken is open to severe criticism from both a public health as well as an ethical point of view.

In summary, obesity is a condition that fulfills all the reasonable definitions of a disease and major medical authorities now recognize obesity as a disease entity. A continuing effort to educate the public to the fact that obesity is a long-term chronic disease is required to overcome the misinformation and stigma commonly associated with this life-threatening condition.

Morgan Downey is Executive Director of the American Obesity Association, Washington, D.C.

Obesity as a Disease Entity is published in the American Heart Journal, December 2001;142:1091-4.

References

[10] American Heart Association. Press Release: 10 AM ET, 1 June 1998. Available at http://www.americanheart.org/Whats_News/AHA_News_Releases/obesity.html

[11] US Department of Health and Human Services, Health Care Financing Administration. Medical procedures: treatment of obesity. Section 35-26. Medicare Coverage Issues Manual. HCFA Publication No.:06. Available at http://www.hcfa.gov/pubforms/06_cim/ci35.htm

[12] US Department of Health and Human Services, Health Care Financing Administration. Medical procedures: gastric bypass surgery for obesity. Section 35-40. Medicare Coverage Issues Manual. HCFA Publication No.:06. Available at http://www.hcfa.gov/pubforms/06_cim/ci35.htm

[13] 42 USC 301 et seq. Available at http://www.access.gpo.gov/uscode/uscmain.html

[14] US Department of the Treasury, Internal Revenue Service. Revenue Ruling 79-151 (1979). Available at http://www.taxlinks.com/revrules.htm

[15] US Department of the Treasury, Internal Revenue Service. Medical and dental expenses (for use in preparing 1999 returns). IRS Publication No.:502. Available at http://ftp.fedworld.gov/pub/irs-99/p502.pdf.

[16] US Department of the Treasury, Internal Revenue Service. Medical and dental expenses (for use in preparing 2000 returns). IRS Publication No.:502. Available at http://ftp.fedworld.gov/pub/irs-pdf/p502.pdf.

[17] National Task Force on the Prevention and Treatment of Obesity. Overweight, obesity and health risk. Arch Intern Med 2000;160:898-904.

Appendix 1

Obesity is listed as a disease or disorder in the following publications: Professional Guide to Diseases, 6^th edition (Springhouse (PA): Springhouse; 1998), p. 874. Current Diagnosis, 9^th edition (Philadelphia: WB Saunders; 1997), states on p. 1460 "Obesity is a serious chronic disease associated with numerous complications and comorbidities that involve most systems of the body." The Encyclopedia of Human Nutrition(San Diego: Academic Press, 1999) has a section on obesity with chapters on Definition; Aetiology and Assessment; Early Obesity and Prognosis; Fat Distribution; and Treatment, Prevention, and Complications of Obesity. (p. 1430-66) The New Encyclopedia Brittannica, Macropaedia, defines obesity. Pathophysiology, 5^th Edition (Philadelphia: Lippincott, 1995) treats obesity on p. 1254-8. Pathology, 3^rd edition, (Philadelphia: Lippincott-Williams & Wilkins; 1998) devotes p. 344-36 to obesity. Human Physiology and Mechanisms of Disease, 6^th edition, (Philadelphia: WB Saunders; 1997) devotes a chapter to Dietary Balances, Regulation of Feeding, Obesity and Vitamins. Nutritional Biochemistry, 2^nd edition (San Diego: Academic Press; 1999) devotes a 40-page chapter to obesity. Women and Health (San Diego: Academic Press; 1999) has a chapter on obesity. On p. 554 The Textbook of Women's Health(Philadelphia: Lippincott-Raven; 1998) states, "Obesity is a chronic disease requiring treatment." The Williams Textbook of Endocrinology, 9^th ed. (Philadelphia: WB Saunders; 1998) has a chapter, Eating Disorders: Obesity, Anorexia Nervosa, and Bulimia Nervosa. Endocrinology, 3^rd ed. (Philadelphia: WB Sauders; 1995) has a chapter, "The Syndromes of Obesity: an Edocrine Approach. The Dictionary of Endocrinology and Related Biomedical Sciences (New York: Oxford University Press; 1995) contains a definition of obesity.

Appendix 2

The Partnership for Healthy Weight Management is comprised of representatives from academia, government, commercial organizations and advocacy groups. It includes American Dietetic Association; American Obesity Association; American Society for Clinical Nutrition; American Society of Bariatric Physicians; Centers for Disease Control and Prevention; Comprehensive Weight Control; Council on Size and Weight Discrimination; University of Alabama at Birmingham's Department of Nutrition Sciences; Division of Nutrition Research Coordination of the NIH; the Federal Trade Commission's Bureau of Consumer Protection; George Washington University's Obesity Management Program; Health Management Resources; Jenny Craig, Inc.; Knoll Pharmaceutical Company; Lindora Medical Clinics; Maryland Department of Health and Mental Hygiene's Division of Cardiovascular Health and Nutrition; Medical University of South Carolina's Weight Management Center; National Heart, Lung and Blood Institute at NIH; National Institute of Diabetes and Digestive and Kidney Diseases at NIH; New York Obesity Research Center; North American Association for the Study of Obesity; Novartis Nutrition Corporation; Shape Up America; Slim-Fast Foods Company; Tanita Corporation of America; St. Lukes-Roosevelt Hospital's Nutrition and Weight Management Center; University of Colorado Center for Human Nutrition; US Food and Drug Administration's Center for Food Safety and Applied Nutrition; Weight Watchers International, Inc.

Appendix 3

Groups joining the American Obesity Association in this filing included the American Association of Bariatric Physicians; the American Society for Bariatric Surgery; Health Management Resoures; Jenny Craig, Inc.; Knoll Pharmaceutical Co.; Novartis Nutrition Corporaton; Obesity Law and Advocacy Center; Shape Up! America; Tanita Corporation of America; Weight Watchers International, Inc.