When food retailer Greggs announced solid interim results just over a month ago, few people will have been overly concerned when the company’s chief executive suggested rising wheat prices may add a penny to the price of a pasty.

But if wheat prices continue to soar, as they have for much of this year, those additional pennies could soon start to mount.

The price of wheat has been soaring since June, following the failure of the Russian harvest. Wheat prices were always going to spike once Russian Premier Vladimir Putin slapped a wholly predictable ban on exports until after next year’s harvest.

Predictable? Absolutely. After all, this is precisely what Russia did following a poor harvest three years ago.

According to economists, the impact of an export ban will distort the Russian market to the detriment of consumers, because it acts as a disincentive for farmers to grow wheat and, in many instances, will actually result in a fall in wheat production — as it did in 2007-08.

But as wheat prices continue to rise, the longer-term outlook for all food prices, not just wheat, looks decidedly inflationary. This has nothing to do with global warming, but very basic demographics.

Essentially, the number of mouths that need feeding is rapidly expanding, while the regions of the world that are home to booming populations are those where arable land is scarcest. The United Nations estimates there are currently a shade under seven billion people to feed across the globe.

That figure is expected to rise to nine billion by 2050, an increase of 28 per cent. However, the UN’s Food and Agriculture Organisation (FAO) forecasts total demand for agricultural products will leap by up to 60 per cent within the next 20 years, significantly faster than the population.

This huge increase is triggered by relentless economic growth. The areas of the world where the population is growing most rapidly also happen to be the ones moving out of poverty at an encouragingly speedy pace.

Demand for grain increases at a rate faster than population growth for one fundamental reason — richer people eat more meat.

This welcome, if delicate, combination increases demand for livestock grain feeds over and above that used for human consumption.

Fortunately, the world continues to produce surplus wheat, particularly in the USA, where farmers are this year expected to profit from the Russian shortfall.

Longer-term, however, the picture looks very different, not least because there is little spare land to cultivate, especially in Asia, where most of the globe’s food supply originates.

Of course, because livestock feeds are interchangeable, this could change within a very short space of time. Two years ago, for example, corn prices were at rock bottom, a situation which resulted in many farmers opting to plant wheat instead.

The result is a forecast shortage of corn next year and, as its price too has soared, so wheat is actually beginning to look a less attractive cash crop for farmers. In August, wheat was worth nearly twice as much as corn, per bushel. By late September, the premium had halved, to 44 per cent.

In Europe, wheat is fighting for farmers’ attention with barley, the stock of which is forecast to plunge by 70 per cent to its lowest in at least a decade and rapeseed, of which there is a global shortage.

According to internatonal financial services provider Rabobank this is a major turnaround from last year, when prices for major EU crops had fallen to — or even below — the cost of production, and farmers were withdrawing marginal land.

Does this matter to consumers and investors?

I think it does, and perhaps investors would agree that by exploring how they can help solve the world’s food shortages, rather than become involved in aggressive speculation and some form of neo-colonial land grab, there are actually greater rewards to be had.