For a while last year, I used to walk about a mile across the park every morning and evening to get to and from the tube station. I mentioned this to a colleague – I can’t remember the context – and she said “ooh, you’re good.”

“Well, I enjoy it”, I said, although what I actually wanted to say was “Why are you assigning a moral value to my unremarkable journey to work? In what sense is it good?”

Of course, what she meant was that by choosing to walk rather than take the bus I was behaving in a way that is somehow designated as morally superior. It’s a mark of my own peculiar oversensitivity to the notion that exercise is innately noble that I minded, but mind I did (slightly).

I remembered this earlier today, when I was eating a breakfast croissant at my desk. Croissants are one of the foods that make me realise what it might be like to have a religious experience: they’re so perfect – their shape and texture and colour and weight as much as their flavour – that I almost think they must have been created on a higher plane. There is nothing to touch a good croissant.

Anyway, I was enjoying this one when someone walked past my desk, peered at me solemnly and barked: “naughty!”. I bit back my immediate response, which would probably have had swearing in it, and managed instead to say “it’s only a croissant”.

Both incidents are entirely trivial and neither ruined my day, but they do point to one of the most troubling aspects of our relationship with food, which is the idea that not only are we behaving “badly” or “well” if we eat certain foods, but that this is so widely accepted that other people feel entitled to comment on it. It wouldn’t matter if I were Kate Moss eating a lettuce leaf or Dawn French eating a cow pie: it wouldn’t be up to anybody else to point out to me their interpretation of the moral value of my food choices.

For one thing, unless you’re my doctor and I’m under close dietary supervision, you have no idea what my croissant (or my cake, or my glass of wine, or my lettuce leaf) means in the context of the rest of my diet. Maybe I usually eat three croissants for breakfast and today I’m only having one. Is that “naughty”? Maybe I have an eating disorder and croissants are one of the things I can bring myself to eat. Is that “naughty”?

And, well, for another thing, it’s just plain rude.