There are addictions society gazes upon indulgently – coffee, exercise. There are others it frowns upon – drugs, alcohol. Then there are those that seem comedic – such as dependence upon Diet Coke. Hence the Sun's headline yesterday: "Diet Cokehead: Mum addicted to fizzy pop." Claire Ayton, the paper reported, drank four litres a day until weaned off it by a hypnotherapist.

I don't have Claire's level of addiction. I drink three cans every working day – one on arrival at my desk, another when that one's finished, a third just before lunch. Sometimes, I'll add a fourth in mid-afternoon. And occasionally a fifth at home in the evening. My mother in law thinks it's evidence of a childish palate.

I know why I should lay off. I know that some suspect aspartame, the sweetener used in the drink, has links to depression and cancer. But there's no concrete scientific proof. I know its acidity is linked to a loss of bone density, but again the evidence is disputable.

There are those who believe Diet Coke addiction is psychological; others who believe it's related to the aspartame, which causes the brain to demand more to try to replicate the sugar rush.

But I don't think an interest in health is what motivates people who point at those of us who keep a can at our side instead of a stained mug. It's suspicion of the other: in any office, people who drink Diet Coke instead of tea and coffee are known, because we don't conform to the norm that beyond adolescence, the hot drink is preferable. Five hundred years ago we'd probably have been killed as witches. But it's just a drink. That's all.