WHAT constitutes a substantial meal? This conundrum became a pressing philosophical concern following the imposition of tier two covid pub regulations in England. Government spokesmen made it up as they went along. George Eustice insisted that a Scotch egg counts. Michael Gove said it didn’t, then changed his mind. Robert Jenrick thought a Cornish pasty fitted the bill.

Meanwhile pubs from Penrith to Port Isaac bought up the cheapest freezer food they could lay their hands on to offer ‘Boris menus' that tick the government boxes for as little as £1.99.

The Scottish Government’s definition is, at face value, more coherent. “A main meal would typically be something more than a mere snack – such as a plated meal, usually (though not necessarily) eaten with cutlery, and could include a substantial filled sandwich or panini served with a side such as salad or chips, or a “soup and a sandwich” style meal, as well as other more substantial meals which may have more than one course.”

But then comes the fudge. “A common-sense approach should be taken.”

This doesn’t take us much further forward. The word “substantial” is highly subjective. Your yoga teacher might consider a green salad with some cashews and bean shoots a meal. Your rugby instructor wants steak and eggs.

What about a sausage roll, known in food manufacturing parlance as a “hand-held snack”? A mean publican will plate one up with oven chips to bulk it out. Are we talking heft, volume, calories, weight in the stomach, or adherence to a widely recognised meal formula?

If someone gave me an unadorned Scotch egg as a meal, I’d be disappointed. But although it is small in size and generally served cold as a picnic item, in terms of nutrient-density, a Scotch egg, thanks to its high protein content – meat and egg – is a pretty filling proposition that will amply satisfy appetite for a good few hours. O

f course, I’d rather it came with a side order of salad, some pickle, a bit of slaw perhaps, but these accoutrements, in appetite-sating terms, are more or less irrelevant add-ons, compared to the meat and egg.

Many, maybe most people, would consider a pizza to be a meal, but I’m not one of them. Yes, they are hot, which adds to the sense of meal occasion, but this is a psychological, not a physical reaction.

And, yes, pizza might have a very modest amount of nutrient-rich food on top: melted cheese and cured meat. As we eat a pizza, we might develop a sensation of fullness quite quickly. But am I the only person who struggles to finish an entire pizza yet who feels hungry again a few hours later?

The same applies to a “lunch” that consists of soup and bread. Satisfaction is short-lived. Satiety, a dish’s ability to keep you going for a reasonable time, is surely an acid test for “substantial”.

There are three macronutrient groups in food: fat, protein, carbohydrate. I liken them to fuel on a fire. Fat is the most sustaining. It’s the coal. It will keep the digestive fire burning longest.

Protein is the logs, a slow burner, but not as long lasting as the coal. Carbohydrates are like newspaper. They ignite spectacularly and burn up quickly, but then, as many nutrition experts will warn you, they rapidly become problematic, with sugar coursing through your bloodstream.

Biology apart, what about anthropological considerations, that big world of diverse cultural eating habits? The traditional Anglo-Saxon meal paradigm is meat and two veg. A Sunday roast is its apotheosis. But who wants to pay £10 upwards for that merely because you fancy an alcoholic drink?

Some desperate publicans have argued that hummus and warm pitta bread qualifies as a substantial meal. Nice try. I’d much rather eat that than a microwaved cash-and-carry frankfurter in a cloying bun. But hummus is just one element in a Middle Eastern mezze assembly of starters, or a base for shavings of grilled meat. Nowhere on its home turf is it considered to be a meal in itself.

Most of us would disagree with TV detective Inspector Morse, who famously considered, much to Lewis’s exasperation, that a pint of bitter was a lunch in itself. But when it comes to the knotty matter of substantial meals, would we agree on anything much else?