The number of times families sit down to share the traditional midday meal is in steep decline. But there are reasons why it has been at the heart of domestic culture for centuries

Mothering Sunday marks the halfway point through the Lent fast and is also a traditional time for the family to sit down to a roast. But it is a tradition increasingly honoured in the breach. Each year, the trade journal The Grocer records a further slowdown in the number of times people gather round the dining table to tuck into a joint; another waymark is passed in the seemingly inexorable decline of old-style family meals, left behind by the fashionable appeal of quicker, more sustainable and, for some, more ethical alternatives – choices that do not involve rearing animals on environmentally costly grains and then killing them. This Sunday’s roast at the pub chain Wetherspoon will be the last it offers. After that, it’s off the menu. Roast dinner, good riddance? Be careful what you wish for.

It is true that there are plenty of reasons not to mourn the Sunday roast. A roast with all the trimmings can be, in the wrong hands, a bit of meat of uncertain consistency, viscous gravy and overcooked vegetables. British tastes have become more outward-looking and much more eclectic. We take foods from the Middle East and fuse them with the produce of northern Europe.

We rediscover ancient grains and the joys of shopping in exotic markets and we revive half-forgotten skills like breadmaking. We are open to new tastes, subtle spices, fresh herbs and novel food combinations in a way that would astonish our grandparents; and if declining sales of celebrity cookbooks appear to suggest a slide in our interest in cooking, it could just as well be a reflection of another phenomenon, the rise of the online recipe search. But you can celebrate the joy of the new and still worry about the loss of the old.

Assuming that you eat meat, the Sunday roast at its best is a tasty meal that is, in nutritional terms, mostly good news, and while it may be time-consuming to prepare, it is not difficult. It can’t be wolfed down, either, so families are required to talk to one another. Even more virtuous, it can turn into other meals as the week goes by, sandwiches and shepherd’s pie, a version of kofta and then ultimately soup. Claims that the Sunday roast is cheap may not quite stack up, but it is great value.

There is another reason why the roast is woven into traditional British (and Irish) cultural life: at its best, eating a roast is eating the landscape. It has been an integral part of food culture because it is composed of what flourishes in the British climate and soil. The patchwork of small, hedged fields that still persist in parts of these isles would not be there if there were no farmers rearing sheep and cattle that need protection from the elements and the convenience of enclosure. The vegetables that go with a roast tend to be eaten in season. It is much more likely that your leeks or carrots have come from round the corner than those glorious exotics like perilla leaves or Asian shallots required for a Vietnamese family recipe.

The BBC foodie series Back in Time for Dinner, where a 21st-century family was dropped back through the decades to experience, say, powdered eggs and a world before fridges, recognised how the food we eat and the way we eat it has shaped a whole layer of domestic culture. That is not a reason on its own for keeping alive the tradition of the Sunday roast. But it is worth more than its detractors admit. So if you possibly can, make time for it this weekend.