Fueling up should be healthy for you—and the planet. But how do you figure out the most sustainable diet? Photo: Hannah McCaughey (2), Sang An, Hannah McCaughey
The endless cascade of nutritional information—about localism, vegetarianism, veganism, organic food, the environmental impact of eating meat, poultry, or fish, and more—makes the simple goal of a healthy, sustainable diet seem hopelessly complex. We talked to scientists, chefs, and farmers to get the ultimate rundown on how you should fuel up.
Tim Zimmermann Jan 7, 2016 Outside Magazine
…. Tell me what you eat and I will tell you how you impact the planet. Most of us are aware that our food choices have environmental consequences. …. Are organic fruits and vegetables really worth the higher prices, and are they better for the environment? If I’m a meat eater, should I opt for free-range, grass-fed beef? Is it OK to buy a pineapple flown in from Costa Rica, or should I eat only locally grown apples?
The science of food’s ecological footprint can be overwhelming, yet it’s important to understand it. For starters, in wealthy societies food consumption is estimated to account for 20 to 30 percent of the total footprint of a household. Feeding ourselves dominates our landscapes, using about half the ice-free land on earth. It sends us into the oceans, where we have fished nearly 90 percent of species to the brink or beyond. It affects all the planet’s natural systems, producing more than 30 percent of global greenhouse gases. Farming uses about 70 percent of our water and pollutes rivers with fertilizer and waste that in turn create vast coastal dead zones. The food on your plate touches everything.
“If you look at the heavy-hitter list of global-scale changes that are human induced, how we feed ourselves is invariably near the top,” says Peter Tyedmers, a professor at Dalhousie University’s School for Resource and Environmental Studies (SRES) in Halifax, Nova Scotia, who has been studying the world’s food systems for 15 years. “But the great thing about food is that we have choices, and we have the opportunity to effect change three times a day.” ….….Here’s a sense of what the planet might reap in return. A 2015 study conducted by the journal Frontiers in Nutrition concluded that a diet that is vegetarian five days a week and includes meat just two days a week would reduce greenhouse-gas emissions and water and land use by about 45 percent…. Does eating grass-fed, free-range meat let you off the hook? Not really, because meat takes a toll no matter how it’s raised. Studies actually show that a factory-farm animal emits fewer greenhouse gases than a free-range one, because it lives a shorter life. But Greg Fogel, a senior policy specialist at the National Sustainable Agriculture Coalition, points out that factory farms in the U.S. produce 13 times as much sewage as the entire human population and that environmental impact is about more than greenhouse gases. “The meat you do eat should be grass-fed meat from managed grazing operations,” he says. “Rotational grazing systems recycle manure as fertilizer, improve wildlife habitat, and enhance plant root systems, increasing soil quality, water infiltration and flood control, and carbon sequestration.”… As it happens, the seafood with the smallest carbon footprint is frequently the seafood that’s best to eat if you’re looking to reduce pressure on wild fisheries…. Clearly, eating less meat has big environmental payoffs. But what about not eating it at all? I’d never crunched the numbers to find out how much more climate-friendly a plant-based diet really is. The results are telling. For example, in the Frontiers in Nutrition study, researchers compared the greenhouse-gas, water, and land footprints of a balanced 2,000-calorie vegetarian diet, including eggs and dairy, with those of a balanced 2,000-calorie omnivore diet that included one serving of meat per day: a 5.3-ounce steak. The vegetarian diet reduced greenhouse-gas emissions by 63 percent and required 61 percent less land and 67 percent less water.
Another study, in the European Journal of Clinical Nutrition, also compared an omnivorous diet to a vegetarian one. It considered a broad array of environmental impacts beyond climate change and land use—including cancer rates, effect on the ozone layer, and waterway pollution—to produce a more complete model. It concluded that the vegetarian diet had just 64 percent of the environmental impact of the omnivore diet…
….Plant-based protein choices also carry different environmental costs. Wheat accounts for one-fifth the greenhouse-gas emissions of water-thirsty rice per gram of protein. Legumes are even better, at one-quarter the emissions of wheat. Being thoughtful about protein alternatives yields even more environmental payoff. Lentils and chickpeas, for example, are better than soybeans at fixing nitrogen in the soil and help you avoid soy’s GMO issues. And quinoa is packed with protein and grows well in a variety of soils…..
…Organic farming, Nichols tells me, is really about the health of the soil and the ecosystems producing our food.
Nichols wants to show me the difference between soil from conventional agriculture, which uses chemical fertilizers and pesticides, and soil from what Rodale calls regenerative organic agriculture, which uses natural pest management, extensive cover crops, and natural fertilizer like manure. …
…according to one analysis I found, buying local can reduce the impact of vegetable production by 10 to 30 percent. Other researchers have calculated that produce moving through the national transportation network that supplies large grocery stores travels an average of about 1,518 miles and emits five to seventeen times the greenhouse gases of regional and local food distribution. In contrast, locally sourced foods travel an average of just 45 miles.
So it makes sense to buy local whenever possible, another reason to spend time at the nearest farmers’ market. If you’re really dedicated to sustainable eating, that means eating seasonally as well. No more grapes and strawberries from Chile in February….
You’re Throwing Away Too Much Food
No matter where you come down on meat, organic, and shopping locally, there are two powerful sustainability strategies you can put to work right now. The first is to eat less. If the average omnivore, who eats around 3,500 calories a day, instead ate a diet closer to his basic nutritional requirement of 2,500 calories, he would likely reduce his environmental footprint by about 30 percent. An active person who works out daily needs closer to 2,800 calories, yielding a roughly 20 percent cut.
The second strategy: waste less. In the U.S., 40 percent of food—worth an estimated $165 billion—is thrown out every year. It’s an environmental and social-policy tragedy.
According to the USDA, which in September announced an initiative to try and cut American food waste in half, the average family of four trashes two million calories a year, worth nearly $1,500. As a result, 25 percent of America’s water is used to produce food that is never eaten, and an estimated 28 percent of the planet’s agricultural land is used to grow food that ends up in the garbage. Food is the single largest solid-waste component of America’s landfills—an estimated 80 billion pounds—and emissions from it are equivalent to the greenhouse-gas output of 33 million cars. ..
…Stop worrying so much about not getting enough protein…Buy organic food whenever you can. Source your food as locally as possible, and eat seasonally to avoid racking up major food miles. Eat less and waste less. Be open-minded and creative about new cuisines. Relax. Have fun. Sustainable eating isn’t synonymous with masochism. ..