The American Medical Association (AMA) designated obesity a disease in 2013 and as a result, the idea that obesity is caused by insufficient willpower, lack of discipline, and bad choices began to transform. The headlines, “AMA Recognizes Obesity as a Disease” were catapulted across both academic and mainstream media. Obesity was no longer a conversation topic tucked away in a dusty corner but was instead sprinkled across national news for the public to scrutinize. From “TED Talks” to The New York Timesobesity specialists were asked to “weigh in” on this groundbreaking and somewhat controversial topic and to answer the question, “is obesity a disease?”

Now, four years later, the debate continues. Is obesity a disease? For some, obesity as a disease invalidates the importance of discipline, proper nutrition, and exercise and enables individuals with obesity to escape responsibility. For others, obesity as a disease is a bridge to additional research, coordination of effective treatment, and increased resources for weight loss.

According to Merriam Webster, a disease is “a condition . . . that impairs normal functioning and is typically manifested by distinguishing signs and symptoms.” In defining obesity specifically, one of the most comprehensive definitions is provided by the Obesity Medicine Association in the Obesity Algorithm. Obesity is defined as a “chronic, relapsing, multi-factorial, neurobehavioral disease, wherein an increase in body fat promotes adipose tissue dysfunction and abnormal fat mass physical forces, resulting in adverse metabolic, biomechanical, and psychosocial health consequences.”

Individuals with obesity have an increased accumulation of fat not always attributable to eating too many calories or lacking physical activity. Individuals with obesity experience impaired metabolic pathways along with disordered signaling for hunger, satiety (the feeling of fullness), and fullness (the state of fullness). For many, efforts to lose weight are met with unyielding resistance or disappointing weight regain. This is demonstrated by the follow-up body composition results of contestants on “The Biggest Loser.” As contestants lose even as much as 230 pounds, their body’s response is a slower and less efficient basal metabolic rate. This occurs in an effort to return the body to its previous condition of obesity; it’s a counter-effort by the body that makes weight gain easier and weight loss harder.

The pathology of obesity is vast and varies based on the cause of weight gain. There is not just one type or cause for obesity. Obesity sub-types include congenital, stress-induced, menopause-related, and MC4R-deficient, to name a few. Obesity is related to genetic, psychological, physical, metabolic, neurological, and hormonal impairments. It is intimately linked to heart disease, sleep apnea, and certain cancers. Obesity is one of the few diseases that can negatively influence social and interpersonal relationships.

Why obesity is a disease is becoming more evident as we increase our knowledge of fat mechanics. To successfully confront the obesity pandemic will require attacking the disease and its manifestations, not just its symptoms.

Do you consider obesity a disease? At the end of this Medscape article, you can take a short survey and view the results to find out where you stand compared to other physician specialties.

This blog article was originally written by Dr Melody Covington MD for the Obesity Medicine Association and can be found in their weight management blog section.