Why do we think obesity is a disease?

First, let's define our terms. Dictionaries agree: obesity is excess body fat. It is not defined as a behavior. However, many people use the term obesity as short-hand for overeating or lack of exercise. But that is not its definition.

Consider this: most people can distinguish between smoking and lung cancer. One is a behavior and one is a disease. Or problem drinking of alcohol and liver disease. One is a behavior and one is a disease. Sunbathing without protection is a behavior; skin cancer is a disease.

Second, obesity - the excess accumulation of body fat - fits all the definitions of "disease." How is "disease" defined? Most dictionaries, general as well as medical, define a disease as an interruption, cessation or disorder of a bodily function, organ or system. Obesity certainly fits this definition.

Some dictionaries have a more precise definition. Stedman's Medical Dictionary says that to be a disease it should have at least two of the following three features:

• recognized etiologic agents
• identifiable signs and symptoms, and,
• consistent anatomical alterations.

The "recognized etiologic agents" for obesity include social, behavioral, cultural, physiological, metabolic and genetic factors.

The "identifiable signs and symptoms" of obesity include an excess accumulation of fat or adipose tissue, an increase in the size or number of fat cells, insulin resistance, increased glucose levels, increased blood pressure, 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. One is also likely to find shortness of breath and back pain.

The "consistent anatomic alteration" of obesity is the increase in body mass. Therefore, obesity meets all three of the dictionary criteria for disease.

• For a medical description of obesity, see the Merck Manual.

Who Considers Obesity a Disease?

Obesity is recognized as a disease in the U.S. and internationally by government, health organizations, researchers and medical professionals.

AOA and Shape Up America!

• The AOA and Shape Up America! collaborated to publish Guidance for Treatment of Adult Obesity, which states:

  "Obesity is a disease afflicting millions of Americans and causing a great deal of pain and suffering. Despite evidence to the contrary, many people view obesity as a lack of willpower on the part of the individual. As a result, obese persons are frequently the object of prejudice and discrimination."

National Institutes of Health (NIH)

• In a 1985 consensus statement on the Health Implications of Obesity, NIH declares:
  
  "Formerly, obesity was considered fully explained by the single adverse behavior of inappropriate eating in the setting of attractive foods. The study of animal models of obesity, biochemical alterations in man and experimental animals, and the complex interactions of psychosocial and cultural factors that create susceptibility to human obesity indicate that this disease in man is complex and deeply rooted in biologic systems. Thus, it is almost certain that obesity has multiple causes and that there are different types of obesity."
  
  
• The NIH's National Heart, Lung and Blood Institute's Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults, state:
  
  "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."

National Academy of Sciences' Institute of Medicine

• The National Academy of Sciences' Institute of Medicine formed a committee to evaluate the treatment and prevention of obesity. In their report, Weighing the Options, the committee 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. Unfortunately, the lay public and health-care providers, as well as insurance companies, often view it simply as a problems of willful misconduct - eating too much and exercising too little. Obesity is a a remarkable disease in terms of the effort required by an individual for its management and the extent of discrimination its victims suffer."

Federal Trade Commission (FTC )

• The Partnership for Healthy Weight Management, a coalition of organizations led by the FTC developed Voluntary Guidelines for Providers of Weight Loss Products or Services. The Partnership states:
  
  "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." The guidelines were established to "promote sound guidance to the general public on strategies for achieving and maintaining a healthy weight."

Maternal and Child Health Bureau

• An expert committee was formed by the Maternal and Child Health Bureau, a branch of the U.S. Department of Health and Human Services, at a March, 1997 conference on obesity in children and adolescents. Committee members were chosen for their clinical and research experience in the field of pediatric obesity to develop guidance on assessment and treatment for physicians, nurse practitioners, dietitians/nutritionists, and others who care for overweight children. The committee stated,
  
  "obesity represents a chronic disease," and "obesity in children and adolescents represents one of the most frustrating and difficult diseases to treat. "

World Health Organization (WHO)

• A WHO Consultation on Obesity reported:
  
  "Obesity is a chronic disease, prevalent in both developed and developing countries, and affecting children as well as adults. Indeed it is so common that it is replacing the more traditional public health concerns, including undernutrition and infectious diseases, as one of the most significant contributors to ill health."
  
  The WHO publishes the International Classification of Diseases (ICD-9-CM), which lists Obesity and Other Hyperalimentation as an Endocrine, Nutritional, Metabolic and Immunity Disease. The ICD-9-CM is recommended for use in all clinical settings, and is required for reporting diagnoses and diseases to all U.S. Public Health Service and Health Care Financing Administration programs. The World Health Organization recently included the Metabolic Syndrome in ICD-10 (#277). Obesity is a component of the Metabolic Syndrome.

American Heart Association (AHA)

• In June 1998, the AHA added obesity to the association's list of major risk factors that people can control to prevent death and disability from coronary heart disease, the cause of heart attacks. Other major risk factors include smoking, high blood cholesterol, high blood pressure, sedentary lifestyle. According to Robert H. Eckel, M.D., vice chairman of the AHA's Nutrition Committee:

"Obesity itself has become a life-long disease, not a cosmetic issue, nor a moral judgement — and it is becoming a dangerous epidemic."

American Academy of Family Physicians (AAFP)

• The AAFP Congress, the Academy's policy-making body, adopted a policy on obesity stating:

"The AAFP recognizes obesity as a disease and a national health risk for premature death; will support CME programs on childhood obesity; and promotes nutritionally balanced meals, decreased TV viewing and increased physical activities for obese children."

American Society for Bariatric Surgery (ASBS)

• The ASBS states in their Rationale For The Surgical Treatment Of Morbid Obesity:
  
  "The physiologic, biochemical and genetic evidence is overwhelming that clinically morbid obesity is a complex disorder."

The American Society of Bariatric Physicians (ASBP)

• ASBP states in their Frequently Asked Questions:
  
  "Recognized since 1985 as a chronic disease, obesity is the second leading cause of preventable death, exceeded only by cigarette smoking. Obesity has been established as a major risk factor for hypertension, cardiovascular disease, diabetes mellitus and some cancers in both men and women."