What can be said in favour of the idea that obesity is simply and straightforwardly a disease in itself? The first is that there is an undoubted genetic component to the tendency to obesity – as there is to many other characteristics, of course, though usually it is only undesirable ones to which this argument is applied. We all know people who eat like horses and never put on weight. There are also genetic conditions that lead sufferers to have a voracious and unassuageable appetite.
The second is that there are discrete illnesses that lead to weight gain: hypothyroidism, for example, or Cushing’s disease. When treated, people with these diseases tend to lose the weight that they have gained.
The third is that our diet has changed. Highly processed, sugary, fatty food now makes up a large proportion of people’s diet, which it used not to do. Because of this, increasing levels of obesity are a worldwide phenomenon, though some countries are more affected than others. Obesity having increased almost exponentially in the past few decades, it is therefore tempting to think of it as an epidemic, like Covid.
But epidemic spread is a social as well as a medical phenomenon. Not every condition that spreads rapidly – tattooing, for example – is a disease, even if it has unhealthy effects.
What lies behind what Edmund, in King Lear, called “an admirable evasion of whoremaster man to lay his goatish disposition to the charge of a star”?
There are three main reasons. The first is that it appeals to us all because it absolves us from our own responsibility for our weaknesses or crimes. Whenever we do anything wrong, our first inclination is to find an excuse for ourselves or blame someone else.