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10 Calories in, 1 Calorie Out - The Energy We Spend on Food

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


In December, I attended Michael Pollan's lecture at the University of Texas’s Bass Concert Hall. My friend, Katie, had called me that morning to ask if I would be interested in joining her for the lecture - she knew that I had read three of Pollan's books on food and had also found out that there were $10 student tickets to be had for the lecture. Long story short at 7:40pm I found myself zipping down Guadalupe with Katie for my first Bass Concert Hall event in my tenure at UT.

Pollan's lecture was interesting, engaging and funny. This was not surprising to me, after having read his books. The bags of groceries that he brought from the Fiesta across I-35 brought in the usual laughs ("Venom" who knew it was a drink??) and groans (Twinkies... ahh, the infamous Twinkie). But, of all the things that he said about "food-like substances" – the things that trick you into thinking that they are food, but have very few similarities with the real thing - and the problems with the Western diet, the thing that stuck in my head was the following....

10 calories in, 1 calorie out


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According to Pollan, for every calorie of food that is produced in the United States, 10 calories of fossil fuel energy are put into the system to grow that food. By no means a break-even system.

I was chewing on this factoid as we left the lecture, musing through how our agriculture industry works today. We grow food - corn, wheat, sugar - and, while some of it grows wild and free with no inputs beyond sun, water and the nutrients that the soil provides, the majority of the food that we produce requires significant energy inputs from us.

And, even after this food is produced (at an energy cost of 10:1), most of it does not come to our tables in its whole, natural form. Instead, the majority of this food is sent to a plant for processing into what Pollan likes to call "food-like substances" (at an additional energy cost). For the purpose of this post, I won't get into what is and is not food – feel free to check out his books to explore this concept - but I would like to discuss the idea of putting more energy into our food than we are getting out of it.

10 calories in.... 1 calorie out...

If I am like the rest of the US, my household will throw away 1.5 pounds of this energy intensive food each day. While this pound and a half might seem small, when totaled over a year (and over the 300+ million people that live in the U.S.) these pounds represent a huge amount of wasted energy. Today, the food that Americans throw away represents approximately 2% of the energy we use in this country. That's enough embedded energy to power two Switzerlands.

And, when looking at the content of the food that we eat and waste, we see another interesting trend. Over the past four decades our tastes in food have shifted - away from coffee, eggs and milk to more sweet and fatty foods.

As Michael Pollan pointed out in his lecture, this shift in what we eat has led to high levels of obesity and all of the associated health risks (diabetes, high blood pressure,...). And, simultaneously, our agricultural systems have evolved into an energy intense food system where we spend 10 calories for every 1 calorie that we produce. A lot of food. A lot of energy. A lot of waste. Doesn't sound very sustainable to me.

[Bora Zivkovic posted a review of one of Michael Pollan's books, titled the Omnivore's Dilema, on his "Blog Around the Clock" today.]

Picture Credit:

  1. Photo of Michael Pollan pouring “black gold” © by Kevin Krejci and used under this Creative Commons license.

  2. Photo of cropland © by Tobyotter and used under this Creative Commons license.

  3. Food waste picture by Nick Saltmarsh and used under this Creative Commons License

  4. Chart from the USDA

[A version of this post was originally published on December 10, 2010]