It’s impossible to name the most nutritious foods. After all, individual foods only provide parts of a healthy diet: Some foods don’t contain protein; others don’t contain iron or zinc. Similarly, it’s impossible to put together a list of the most sustainable foods that have a low environmental impact. “You have to talk about diets. You have to talk about all of the factors that influence sustainability,” explains Professor Fergus Clydesdale, a food scientist at the University of Massachusetts at Amherst.
The original definition of sustainability is “meeting the needs of the present without compromising the ability of future generations to meet their own needs” according to the landmark 1987 Brundtland Report put together by a U.N. commission, cites Clydesdale. Sustainability comprises a myriad of factors: greenhouse gas emissions, non-renewable energy and minerals, freshwater consumption, land use, ecosystem quality, waste, and nutrition.
Based upon these factors, general recommendations for a more sustainable diet include replacing animal protein with plant protein, eating a nutritious diet, and reducing waste. With instruction from Clydesdale, a prototype sustainability and nutrition-focused diet by Nestle called the LiveWell diet (presented at the 2015 International Life Sciences Institute annual meeting) and United States Department of Agriculture research, we’ve put together a guide for eating more sustainably for Earth Day.
Get more protein from grains, legumes, potatoes, and dairy
One of the most effective ways to make your diet more sustainable is to increase your protein intake from grain products, vegetable products, and dairy. “The growth of plants use less input [food, water, land and energy] than animals,” explains Clydesdale. “Certainly legumes and grains in terms of getting protein are better sources of getting protein than animals environmentally. And dairy is pretty good, too.”
Clydesdale didn’t specifically note types of foods, but beans, soy, milk, cheese, and yogurt are typically referenced as good non-meat protein sources. Try mixing it up: Dishes with complete proteins include rice with lentils, split-pea soup with brown rice, vegetable chili with cornbread, pasta salad with kidney beans, and potato salad.
As for meat and seafood, fish, chicken, and pig are much better than beef from a sustainability standpoint. Animal feed to food conversions—or the amount of output (meat or diary) from animal feed—depict this most clearly. 100 kg of feed will produce 70 kg of fish, 65 kg of dairy milk, 40 kg of chicken, 20 kg of pig, and just 10 kg of beef, according to Nestle research. (The research notes that a “large portion of farmed fish feed is fish meal, or crushed smaller fish from wild catch,” which isn’t exactly a model for sustainability either.) Looking at it another way, one study says that while beef accounts for four percent of the food supply by weight, it’s responsible for 36 percent of U.S. diet-related greenhouse gas emissions.
Focus on nutrition: Eat more vegetables, fruits, whole grains, legumes, and nuts
At its core, sustainability focuses in on “foods that will sustain life, i.e. nutritious foods,” notes Clydesdale. Broadly speaking, Americans need to eat a more plant-based diet according to a 2015 report from the USDA’s Dietary Advisory Committee. Furthermore, sustainable diets focus more on plant-based foods—such vegetables, fruits, whole grains, legumes, nuts, and seeds—and lower on animal-based foods, according to this research.
“Current evidence shows that the average U.S. diet has a larger environmental impact in terms of increased greenhouse gas emissions, land use, water use, and energy use, compared to the [recommended] dietary patterns,” says the report. “This is because the current U.S. population intake of animal-based foods is higher and plant-based foods are lower, than proposed in [the USDA’s advised diets].”
For a more sustainable, healthy diet, the USDA recommends making half of your plate fruits and vegetables. A variety of vegetables is key: dark green, red and orange, legumes (beans and peas), and starchy ones (potatoes, corn). Fruits (especially whole fruits), grains, low-fat dairy (including milk, yogurt, and cheese) and a variety of proteins (including seafood, lean meats and poultry, legumes, nuts, seeds, and soy products) are other necessary elements, according to the USDA.
Reduce food waste
The average American family throws away a quarter of the food it purchases, according to the Natural Resources Defense Council. And, on a broader scale, nine billion people will live on the planet by 2050. “We’ve got to produce as much food in the next [three decades] as we’ve produced in all of history,” explains Clydesdale. “We can’t afford to have that food wasting. We can’t afford to just have it sitting on shelves until it goes bad. So we’re going to have to use technology to stabilize it.”
At home, Clydesdale has one simple, cost-effective tip for consumers: Use more canned and frozen foods. “Whether the food is local or not local, if you can it and freeze it, you have less food waste because there’s less food waste when you trim the food—you get it in and freeze it or can it quickly and when you use part of it, you don’t throw the rest of it out,” he says. “It doesn’t go bad. You can keep it for quite a long time. You really reduce food waste by doing that.”
Header image courtesy of The Movement Menu.