Every so often I see a news report about the "Negative Calorie Foods" diet. Basically, it suggests, certain foods take more calories to chew and digest than they provide. Celery is often given as an example. After eating a few sticks of celery – plain, of course, not slathered in mayonnaise or peanut butter or whatever else – you're thinner than you were before, or so the theory goes.

Now, all you have to do is think about it for a few minutes to realize the silliness of this approach. However many calories you burn by digesting celery, it's pretty trivial compared to the calories you burn by breathing, running your brain, keeping your body temperature constant, and repaired damaged tissue. These are all automatic, unconscious functions that we're doing all the time.

The caloric expenditure required to digest a "negative calorie food" really pales in comparison with other motor functions, like walking, lifting, bending, climbing stairs, etc. Focusing on lettuce is like trying to get rich by looking for pennies on the ground to drop into a piggy bank, instead of saving and investing your paycheck.

So instead of getting caught up in figuring out which foods theoretically oppose our evolutionary desires by leaving us with less energy after eating them than before, let's focus on eating a variety of plants prepared in delicious ways, and get our exercise through natural and joyful movement.

The Nasty Raspberry Patch

Next to my house is the community organic garden. I confess, I've never been much of a gardener by inclination. I love the thought of a garden, and one year I got hooked on Square Food Gardening and bought a bunch of pine boards of the wrong kind and lots of sand, vermiculite and peat moss, and then kind of lost interest when the bugs became as interested in my produce as I was.

But I do love raspberries, and when Mia pointed out that we should be having a fall harvest right now, and we're not because of all the weeds, I sprang into action.

Not that I think for a minute that you don't believe this part of the story, but just in case, here's a photo:

Mia took this photo minutes after I began working, perhaps intuiting that if this moment were to be captured for future generations, she shouldn't wait until I figured out that pulling morning glory and thorny blackberry plants wasn't as much fun as it seemed.

As the afternoon wore on, and the morning glories seemed to grow back faster than I could pull them, I reflected on the concept of negative calorie food in a new way.

There was no way this raspberry patch was going to compensate me, calorically, for my stint of weeding.

There was no way my Square Foot Garden back in New Jersey ever provided more calories than I spent on it: measuring, cutting and nailing boards; shlepping (that's a Yiddish word that means "shlepping") the huge and cumberson bags of peat moss and sand and vermiculite (what the heck is vermiculite, anyway – it doesn't look or sound organic to me); laying the twine latticework and propping up the electrical conduit for the climbing plants; prepping and sowing the seeds; daily inspections, weeding and watering; eventual harvesting; record-keeping; repairing and replacing the boards which were the wrong boards because they warped and fell apart, leaving the 2-foot bed looking, by November, like a miniature abandoned tel in the weedy and forlorn landscape.

As I slowly won tug of war after tug of war with the morning glories (such a sweet, innocent name for such a wily adversary!) and uncovered the naked, barren raspberry plants, I began to wonder that the human race ever got more calories than we spent in pursuit of sustenance.

You want a negative calorie food? Try growing it yourself!

The Story of Life on Earth

In The Omnivore's Dilemma, Michael Pollan writes:

At its most basic, the story of life on earth is the competition among species to capture and store as much energy as possible – either directly from the sun, in the case of plants, or, in the case of animals, by eating plants and plant eaters. The energy is stored in the form of carbon molecules and measured in calories. The calories we eat, whether in an ear of corn or a steak, represent packets of energy once captured by a plant.

When you look at things this way, you realize how messed up our society is. More than half of us are engaged in a profoundly anti-survival campaign – to capture and store as little energy as possible. How did we get to this point? How did we become such efficient producers of food that we had to build cathedrals to pointless energy expenditure (gyms and fitness centers) just to burn off the excess energy?

The answer is, of course, that we didn't become efficient at all. We just borrowed the sun's energy that the earth had been saving for millions of years, and unleashed it all at once.

Instead of muscle power, we use fossil fuels. Fossil fuels – oil and natural gas, principally – represent the sun's energy that was stored as carbon by ancient plants and animals.

Our modern food chain runs on this borrowed – and quickly diminishing – energy source. Industrial agriculture uses fossil fuels to make fertilizers and pesticides, to run the tractors and combines and threshing machines, to transport the plants from the farm to the animals in the feedlot, and to bring the animals from the feedlot to the processing plant (butchery, if you don't care to euphemize the slaughter of billions of animals), and to package it all up and convert it into the processed convenience foods that comprise the standard Western diet.

There's two big problems with this picture, of course. First, it's not sustainable. I can live very well for a while as I squander my inheritance, but when the money runs out I'm in big trouble.

Second, the release of millions of years of stored energy in the blink of a geological eye – the last 60 years – is wreaking profound and long-lasting and unpredictable damage on our planet. Especially the parts of our planet that support us.

Back to the Negative Calorie Foods

So it turns out that virtually everything we put into our mouths is a negative calorie food. Look at the corn that feeds our livestock and that gets turned into the majority of our calories, through corn syrup, corn starch, glucose, maltodextrin, lactic acid, lecithin, maltose, caramel color, xanthan gum, Cheez Whiz, margarine, salad dressings, mustard, cakes, gravy, frosting, etc. (According to Pollan, "There are some forty-five thousand items in the average American supermarket and more than a quarter of them now contain corn.")

Corn requires more calories to grow than it provides. So do all the other foods in the industrial food chain. We're an overweight and obese society not because we've grown fat genes or because we've all lost our willpower, but because we've figured out how to plunder the earth's energy stores more ruthlessly and efficiently than any previous generation.

When the oil runs out, which it will someday if we haven't destroyed the earth's ability to support us before it does, we'll be faced with the fact that our survival, our future, will depend on gardeners more skilled than me.  People who can coax more accessible calories from the sun than the effort it takes. Local farmers, local gardeners, local distributors.

We're All Gardeners

I was chatting the other day with Greg Lynn Weaver, spiritual director of the PeaceWeavers. In a completely different context, he remarked that all of us are the gardeners of our own lives.  We don't get to choose the patch of soil it is our destiny to till, but we do get to choose what to plant.

We plant things, and we pull weeds. Some of those weeds were sown by our parents, by our siblings, by our churches, by the media, by our peers. We don't need to let  them grow and strangle the raspberries of our soul.

But gardening is not for the faint-hearted or the chronically comfortable. We can end up sweaty and tired, scratched and bitten. It takes more consciousness than most of us are in the habit of mustering, and a fierce will, and a deep faith in the future.

But in the end, as Voltaire reminds us at the stunningly tender conclusion of Candide, our little patch of life is all we have. After suffering in turn from illusion and disillusion, Candide distills his wild and painful life's lessons into a simple directive: "Let us cultivate our garden."

My friends, look around at this gorgeous planet we're blessed with. As Greg Lynn says frequently, it's a heavenly body. It's not a prison planet. We're not here to be punished, we're here to walk in beauty and love.

The nasty raspberry patches of our own lives represent invitations: to turn weeds into sustenance, neglect into loving consciousness, and the daily gift of the sun – undeserved grace if I've ever seen it – into our own vibrant and healthy flesh and bones.

Let us cultivate all our gardens.