Finding The Calories To Feed A Hungry World, Hidden In Front Of Our Faces

A new analysis concludes with an astounding statistic: Our appetite for animal products and fuel are the two main reasons why we can't feed another 4 billion people on this planet a healthy 2,700 calories a day.

The food system is set to come under growing strain as world populations grow and appetites for meat increase—studies show that to meet demand, we could need 60% to 120% more crops by 2050.

Of course, producing more food isn't the only answer. Society could try to minimize the incredible inefficiency of agriculture today. Not only do we literally waste one-third to one-half of all food we produce, but of the rest, much of it doesn't even go to feed people, a new study finds.

The calorie economy, it turns out, is dominated by livestock. The researchers at the University of Minnesota show that more than a third of all calories we produce goes to feed animals, with only 12% of that actually contributing to calories consumed by humans. Rearing meat isn't a good use of scarce resources (how ever much you might like your steak). An animal needs to eat 30 calories for every one calorie humans get back in edible food.

The study finds that growing food on cropland currently devoted to feeding animals and making biofuels could release an enormous amount of extra calories—in total, feeding as many as 4 billion people. But even more modest shifts, like rearing less beef and more pork and chicken, could be useful. The researchers estimate that replacing feedlot beef production with chicken and pork would feed 357 million additional people, based on a 2,700-calorie daily diet. Ending meat production completely, and substituting in milk and eggs, would feed 815 million people.

"We essentially have uncovered an astoundingly abundant supply of food for a hungry world, hidden in plain sight in the farmlands we already cultivate," says Emily Cassidy, lead author of the paper published in the journal Environmental Research Letters.

She is keen to point out that the research isn't some vegetarian manifesto. At bottom, it is intended to show how shifts within the current system could pay as many dividends as expanding it. That's worth bearing in mind the next time someone says the world is running out of food.

[Image: Flickr user Kevin Walsh]

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  • 2kjz

    Diet for a Small Planet was published back in 1971 and the author argued then that a plant-centered diet was healthier and a more effective way to use our resources.  I still own my small paperback copy and have made many of the recipes.  There is a 20th anniversary edition.  

  • oderb

    I wish the analysis had factored in some proportion of beef being raised on grass , which utilizes calories that would otherwise
    be unavailable for humans to eat - in addition to being much healthier and more humane. 

  • lxndr

    The key is the feedback loop of population and food production. They drive one another. Being more efficient in calorie utilization will also encourage population growth.

    This is too simple an explanation - more links to other sources is essential. For example, Vaclav Smil has written a number of books on this topic.

    This is not a new discovery - it is a rediscovery of something we've known for a hundred years. What is new is the addition of increased sanitation levels and new medicines, which both dramatically increase life expectancy and population size.

    But it's excellent having this topic before us once again. Human population growth tracks perfectly with species extinction - we are eating them to their death.

  • Sarah Jo

    Decreasing meat production is not a viable or realistic option when the world's population is demanding it. With a growing middle class in countries like China & India, people can afford to purchase more meat protein, which we can't forget, is essential to a well-balanced diet. Increases in efficiency, sustainability and technology have allowed the world to enjoy both crops and meat protein, and will continue to do so in the future as the agriculture industry progresses.