What is a disease?

The medical profession argues that obesity is a disease; not everyone agrees.

Is obesity a disease? Or a symptom? Or a risk factor for other diseases? Or just the extreme end of a natural variation?

Opinions vary. Many doctors would say that obesity is itself a disease, causing ill-health. At the other end of the spectrum, obesity acceptance groups argue that there is nothing wrong in being fat and obese people are being unfairly discriminated against and classified as 'ill'.

What is a disease? The question is surprisingly hard to pin down. Some doctors argue that the variability in symptoms arising from obesity, plus doubt about the point at which weight becomes abnormal, suggests that obesity itself should not be considered a disease. They say that 'risk factor' would be more appropriate.

Yet variability in symptoms is common in many diseases, and the public health impact of obesity is hard to question.

The authority in cases such as this is the International Classification of Diseases, produced by the World Health Organisation. Obesity has been included in the ICD since 1948.

Do labels matter anyway? Arguably they do. How people perceive themselves will depend on whether they have a ‘disease’ or not. Potentially, it may also influence their thinking about their condition, perhaps falling into a kind of 'victimhood'. And it has very significant commercial implications. Pharmaceutical companies, for example, can say they are producing therapeutics to treat people in need. The food industry may be accused of making people ill. And the disease label may encourage authorities to consider weight a public health issue rather than a matter for individuals.