The BBC's recent class survey struck me as completely barmy. Like lots of people, I eagerly logged on to the BBC website in order to discover my "new" class (there are seven: precariat at the bottom, elite at the top). You must answer five questions. The first three are about money; the fourth invites you to list the professions of your friends, and the fifth, your pastimes. The first time I did this quiz, naughtily withholding the fact that I've been to opera once or twice, I came out as "technical middle class". The second time, having admitted to the fact that I quite like a blast of Verdi, I came out as "elite". So, go figure.

Why didn't they stick in a question about food? Surely there's no more sure-fire indicator of class in 21st century Britain than where a person shops and what they eat – though admittedly, it was ever thus. It so happens that 2013 is the 100th birthday of Round About a Pound a Week by the Fabian and feminist, Maud Pember Reeves. A survey of the working poor in Lambeth – it's great, and still in print – no fewer than four of its chapters are devoted to diet. They make for unnerving reading today. "The diet where there are several children is obviously chosen for its cheapness," she writes. "It is of the filling, stodgy kind. There is not enough of anything but bread. There is no variety. Nothing is considered but money."

But then I thought about this some more, and I wondered if the sociologists weren't right, after all. A rogue Fray Bentos pie, consumed by some city boy in his bachelor pad late at night, might have made their "results" even battier. A depressing quirk of the British middle classes, if my experience of Pizza Express is anything to judge by, is that they tend to be far snobbier about schools, houses and cars than they are about food. And even people who are very snobbish indeed about food – people like me – eat all sorts of rubbish on the quiet. Food is so much connected to childhood. We cling to the tastes of the past, even as we learn to like new things. Just as it's possible to enjoy Tinie Tempah and Turandot – why shouldn't it be? – so some of us enjoy both white sliced and something artisanal with seeds on it (though not at the same time, obviously). If the BBC's sociologists had asked me to tick items on a list that consisted of quinoa, smoked salmon, nectarines, avocados, Tunnock's Tea Cakes, Findus Crispy Pancakes, tinned spaghetti and Dairylea cheese, I would have marked them all save for quinoa (I gather it's a grain, but it sounds more like a bird to me, and I know in my bones that cooking it would be more trouble than it's worth).

It's all quite complicated, this: nuanced, you might say, if you were a better class of sociologist. The editor of Waitrose Kitchen, William Sitwell, insists he's thrilled with his new columnist, Pippa Middleton, but it seems to me that the kind of people who buy his magazine, however rich, however upwardly mobile, are looking for a certain kind of authenticity, not Let's Pretend To Cook. Equally, just as those who shop at Waitrose undoubtedly have bigger incomes than those who shop at, say, Morrisons – there's a reason why George Osborne chose to mount his defence of benefit cuts before workers from Morrisons – not all of them are in search of Camargue rice and broad bean hummus. I know I'm not.

Waitrose doesn't sell Findus Crispy Pancakes, a delicacy even Hugh Fearnley-Whittingstall, food crusader and Old Etonian, has owned up to loving. But Ocado does, and while I was thinking about this column, I was overcome with longing, and decided to put a few in my virtual basket (sadly, they no longer make the curry-flavoured ones I recall from the 80s; fans must make do with chicken and sweetcorn now). But… what's this? A few deluded souls had rated the dear pancakes, Walter Raleigh-like, as if they were the first people on the planet to unearth this strange new delicacy. Oh, my. They might as well have written "this interesting sausage is apparently made of blood" beneath a picture of a black pudding, or noted that they had found "this large citrus fruit – the grapefruit, as it's often known – somewhat bitter". Two were outraged: "one piece of sweetcorn in the whole pack"; "nothing like the picture". But the third was mighty pleased with his find. "Easy to prepare and tastes nice," he'd reported. Five stars from him. You see? I told you this was a complicated business.