When I was writing my new book Before and After, I made a conscious decision that I wanted my hero to be obese. This is unusual as generations of books and films have made one point very clear: fat people aren't heroes. If you are obese then you have two very specific roles in stories – you are either the comic relief and must look for the nearest puddle to fall into, or you must look on approvingly to what the thin, main character is saying and doing. It’s reached the point where the very idea of an overweight hero is absurd – can you imagine a BMI 30+ Gandalf? Or Batman leaping on a Batmobility Scooter? So why is it so hard for storytellers, who talk a great game about representation to give a starring role to obese people?One obvious point is that society frequently perceives obese people in a negative sense. They are lazy or stupid, they are the butt of the joke. They wouldn’t be capable of chucking a Batarang, or edging their way down a heating duct if their life depended on it. And yet this goes against real world evidence. Sure, obesity has the potential to increase the risk of a number of medical issues, but it doesn’t follow that fat people are therefore stupid or lazy. You only need to switch on the news to see that obese people run the world’s biggest companies and countries – so surely we should be better at perceiving their positive traits?