Does Obesity Equate to Diseased?

2013-06-19T17:07:37+00:00 June 19th, 2013|Weight Loss, Weight Management|
Happy fat woman doing gymnastics

AMA defines obesity as a disease, but can you be “fat and fit”?

Are all obese people unhealthy or ill? While your initial answer may be “yes”, some research does not agree. The idea that a person with a body mass index (BMI) indicating obesity (>30) could be healthier than someone with a normal BMI seems unfounded. This trialed theory of “fat fit” has recently come into light as a medical council agreed to define obesity as a disease rather than a risk factor.

According to a press release, health professionals who attended the annual American Medical Association (AMA) meeting voted almost unanimously to “recognize obesity as a disease state with multiple pathophysiology aspects requiring a range of interventions to advance obesity treatment and intervention.”

While this decision has no legal authority, medical policy and health regulations are commonly established based on the policy stances of the AMA. The hope of defining obesity as a disease is that the endorsement will lead to greater investments and even insurance coverage for someone who is suffering from the ailments of obesity.

With one-third of the US population falling into the obese category, it is at the top of the list of health concerns. However, there is some opposition to the AMA’s decision.

Many health experts argue that the use of BMI is an imperfect measure. Because BMI determines obesity based on height and weight, it neglects body composition. For example, an athlete with a large amount of muscle mass could be classified as obese based on their BMI. In fact, some research has shown that people considered obese can be otherwise fit and healthy.

A major contributor to this “fat fit” theory is data collected from a prospective Aerobic Center Longitudinal Study (1, 2). This study included more than 80,000 participants over a 35-year period. Methods involved anthropometric measurements, lab work, and treadmill maximal testing to determine cardiorespiratory fitness (CRF). The results were surprising—the greatest decline in the mortality rate was related to fitness rather than fatness. In other words, a lean but unfit person was at greatest risk of dying than someone who was obese yet had good CRF.

Another study, the Lipid Research Clinics Study, involved more than 5,000 participants and showed that while fitness did contribute to lowering all-cause mortality risk, it could not completely reverse the increased risk of mortality from increased body fat (3).

Critics of the AMA’s decision to label obesity as a disease also worry about increased health care costs without significantly improving patient outcomes. While obesity is a serious health condition, many believe that it is the result of behavioral habits such as overindulging at meals and living a sedentary lifestyle. Because it can result from personal choices, some believe it should not be classified as a disease.

Nevertheless, the AMA’s decision reemphasizes the urgency in finding a solution to the obesity epidemic and may be the kick that we need to take action.


  1. Blair SN, Kohl HW, 3rd, Paffenbarger RS, Clark DG, Cooper KH, Gibbons LW.: Physical fitness and all-cause mortality: a prospective study of healthy men and women. JAMA 1989; 262: 2395– 2401.
  2. Lee CD, Jackson AS, Blair SN.: US weight guidelines: is it also important to consider cardiorespiratory fitness? Int J Obes Relat Metab Disord 1998; 22: S2– S7.
  3. Stevens J, Cai J, Evenson KR, Thomas R.: Fitness and fatness as predictors of mortality from all causes and from cardiovascular disease in men and women in the Lipid Research Clinics Study. Am J Epidemiol 2002; 156: 832– 841.