Professor of Political Science at the University of Chicago
Con to the question "Is Obesity a Disease?"
"[A]s a disease, obesity is a flawed construct. Consider, for a moment, some of the awkward questions that arise when you call obesity a disease: is someone who is slightly overweight, only slightly diseased? Can someone catch or 'come down' with obesity? Can obesity really be 'cured'? If these questions seem ludicrous, it is because obesity does not readily meet the criteria of disease. According to Stedman's Medical Dictionary, a disease is 'an interruption, cessation, or disorder of body function, system, or organ.' By this definition, if obesity is a disease, then we must assume that, at some level, body fat is pathological. Yet... there is no clear evidence about what level or even how, exactly, adipose tissue is harmful to our health. For some extremely heavy people, their body fat may disrupt their ability to function, particularly their ability to exercise, but for most people their fatness is not a disorder. Indeed, body fat on some parts of the body, such as the thighs, can actually be helpful to sustaining our health. Even Stedman's Medical Dictionary does not call obesity a disease; it is simply known as 'excess subcutaneous fat in proportion to lean body mass' or, at worst, 'a public health problem.'
...Despite the plethora of apocalytpic warnings, there is no clear evidence that, for most Americans, their weight is putting them at any health risk... In truth, we could end the obesity epidemic right now if we desired—all we would need to do is to redefine obesity according to the real criterion of a disease. If we simply classified obesity at a level where body fat is incontrovertibly pathological, only a fraction of Americans would qualify and this 'epidemic' would vanish."
Fat Politics: The Real Story behind America's Obesity Epidemic, 2006