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Meeting the Global Demand for Food: The monumental 22 trillion a day challenge

Humanity has faced many challenges from famine, war and pestilence to climate change and COVID-19. So far we have overcome them all through fortitude, imagination and sacrifice. Now comes the biggest, wickedest, 22 trillion a day challenge.

What is the 22 trillion a day challenge? 

Fortunately, it’s not more burpees than ever attempted in the history of mankind or even the size of the US national debt—that is 32 trillion and counting. We’re talking about calories, the energy content of food, kilocalories, to be precise. 

22 trillion is the number of kilocalories that must be supplied each and every day to meet the basic metabolic energy needs of a human population of 8 billion people, increasing at a rate of 8,000 per hour. 

The number comes from the simple assumption that the average person needs an energy consumption of 2,800 kcals per day from food multiplied by the number of people on Earth. 

An enormous number

The 22 trillion a day challenge applies every single day of every year and continues getting bigger as the population grows and wealth increases. 

22 trillion or 22,000 billion is such an enormous number it’s incomprehensible, rather like the US national debt. 

What is remarkable is that 22 trillion kcal of food energy is delivered daily. It is a miracle of human ingenuity. Millions of tons of food products are grown, harvested, stored, transported, processed, and sold along a six-continent food supply chain that gets food from paddock to plate.

And this keeps happening without a thought from most of us.

Through global disruption from financial crises, errant presidents and even a pandemic, the food production and distribution systems keep supplying the calories such that the 22 trillion a day challenge is met, more or less. 

More or less because not everyone has access to the necessary calories. 

Inequity in the 22 trillion a day challenge

United Nations food agencies State of Food Insecurity and Nutrition in the World 2020 report estimates that about 8.9% of the world’s population—690 million people—go to bed on an empty stomach each night, which is expected to exceed 840 million by 2030.

Meanwhile, data from The Food and Agriculture Organisation of the United Nations (FAOSTAT) shows the average intake of food energy per person in the US is 3,600 calories daily, up a quarter from the level in 1961 and 28% more than is needed for good metabolic maintenance, with growth in consumption of vegetable oils accounting for more than half of the calorie increase.

There is inequity in food availability.

This food inequity for people worldwide exists despite most estimates from production and supply suggesting that global food production is sufficient to meet demand. Poverty reduction to prevent hunger and malnourished people remains a global challenge everyone should prioritise. 

We will come back to this in a moment. 

oat cake cookies that help meet the 22 trillion a day challenge for some people
Photo by Towfiqu barbhuiya on Unsplash

First, let’s focus on the remarkable fact that 22 trillion calories are delivered daily through a dizzying array of production systems and supply chains. 

Here is how it happens.

Natural capital used to meet the 22 trillion a day challenge

Chinese consumers get through 54 million tonnes of pork each year at roughly 30 kg per person, a staggering threefold increase since the 1970s. But this is just an illustration. Everywhere humans have commandeered net primary production (NPP) to channel biomass into foods. 

We clear vegetation, plough fields, add fertilisers and graze livestock on the land unsuitable for crops. We use 50% of the habitable land area for this purpose—one of the reasons rewilding is so tricky.

We call the ability of nature to capture energy from the sun and turn it into biomass natural capital because we use it in our economic systems. And we are so good at exploiting natural capital that 97% of the mammal biomass on Earth is humans and their livestock and the reason for biodiversity loss.

Humans are extraordinarily good at innovating where there’s a buck involved. It’s our superpower. If there is profit, people will find a way to grab a share. Economists call it meeting demand with supply. 

The 22 trillion a day challenge that sustainably FED recognises is not so much the magnitude of the calories needed today, tomorrow, and for a hundred years and more into the future, scary as this is.

Our concern is where all those calories will come from.

Food production involves channelling primary production from photosynthesis in plants into foodstuffs. Fields, feedlots, fisheries and farms of all shapes and sizes generate the calories using applied ecology, typically with additional energy inputs, fertiliser and pesticides.

More simply, calories come from using natural capital with subsidies for nutrients and energy—and the reality is that natural capital is finite

graph of the land area on earth divided into habitable and agricultural land

No matter how we cut and dice it with technologies and pretend that we’ve got access to all sorts of inputs, productive land area is finite, as are nutrients in the soil and the ability of ecological processes to restore them. 

So too are the fossils that provide the energy for the machines, technologies and the manufacture of fertilisers.

The 22 trillion a day challenge is understanding the limits to natural capital and working within them to feed everyone well. 

woman buying fresh fruit at a market stall
Photo by Clem Onojeghuo on Unsplash

What sustainably FED suggests.

That the global six-continent supply chain and close to 500 million subsistence farmers can meet the 22 trillion a day challenge regularly, routinely, day after day, year after year is nothing short of miraculous. 

We built sustainably FED to raise awareness of the challenge and to help address the uncertainty over how long we can keep the miracle alive. 

Agricultural systems have degraded soils, and intensification has caused environmental disruption. There are yield gaps that are hard to close, cultural consequences of production systems, and low resilience in long food supply chains. 

Above all, people are getting in the way of sustainable food. People who chase a buck and promote an economic system that promotes inequality. People who can’t resist the sugary foods that mess with their metabolic health. People who mean well but cannot understand that humans eat animal protein.

It might not be enough to meet the 22 trillion a day challenge with a food system dominated by grains, seed oils and sugar. 

Close to a billion people are food insecure, and another 3 billion are malnourished because while poverty leads to malnutrition, so do empty calories. Fixing inequity in food access and food security will be a high priority, but so will maintaining a healthy diet for everyone.

On this website, over 100 articles dive deep into sustainable food, food ecology and sustainable diet to help you find solutions to the 22 trillion a day challenge. 

As a reader and hopefully a participant on the site, we hope you become a hero in the challenge of everyone’s lifetime.

Hero image modified from a photo by Minna Hamalainen on Unsplash


Mark is an ecology nerd who was cursed with an entrepreneurial gene and a big picture view making him a rare beast, uncomfortable in the ivory towers and the disconnected silos of the public service. Despite this he has made it through a 40+ year career as a scientist and for some unknown reason still likes to read scientific papers.

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