What Does a Sustainable Diet Look Like? Here’s What the Science Says

First, let’s establish what it means for something to be sustainable. The Environmental Protection Agency (EPA) describes sustainability as conditions that support both humans and nature — and that will continue to do so in future generations (1).

For example, a sustainable farm provides nutritious fruits and vegetables that support human health while aiding nature by avoiding the use of pesticides and fertilizers that could harm plants or wildlife.

The farm may also rotate crops to maintain soil health, which makes the farmland usable for future generations.

Similarly, a sustainable diet supports both humans and nature in the short and long term.

Short- and long-term human impact

To support humans in the short term, a sustainable diet must be affordable, accessible, nutritious, and free from harmful compounds like foodborne pathogens (2).

It’s also important that people working in every part of the food system — from farming and packaging to transport, retail, and cooking — make a living wage, receive adequate health benefits, and have safe working conditions (2).

To support humans in the long term, a sustainable diet should minimize the risk of diet-related conditions like type 2 diabetes, heart disease, and cancer (2).

Short- and long-term environmental impact

To protect the environment in the short and long term — which also supports humans, since a healthy environment is crucial for our survival — a sustainable diet should (2):

• minimize greenhouse gas emissions, water use, soil erosion, and pollution
• prioritize animal welfare
• support biodiversity

On an individual level, this means making changes like eating less meat and choosing produce grown without harmful pesticides and fertilizers.

On a larger scale, it means investing in agricultural systems that renew — rather than deplete — the ecosystems to which they belong.

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A sustainable diet supports the natural world, as well as human well-being, by minimizing inputs like pesticides and ensuring adequate working conditions for people in the food industry. Its scope is both short- and long-term.

Sustainable diets should focus on plant foods. Still, this doesn’t mean you need to cut out meat or dairy entirely.

A diet high in plant-based foods — fruits, veggies, grains, legumes, nuts, seeds, and any items derived from these foods — and low in animal foods is associated with better human and environmental health (3).

Nearly 40% of the Earth’s land is used for agriculture — both crops and livestock — and 35% of all greenhouse gas emissions come from food production. Of those emissions (4, 5):

• 57% come from animal production
• 29% come from plant-based foods
• 14% derive from other land uses, such as growing rubber or cotton

Plus, the United Nations projects that food production will have to increase by about 70% by 2050 (compared with 2009) to meet the increasing food demands of the world’s population (6).

According to the EAT-Lancet Commission (a group of 37 prominent scientists from 16 countries), the best way to reduce both greenhouse gas emissions and agricultural land use is to (3):

• rely less on livestock, which take up more land and create more greenhouse gasses — particularly methane and nitrous oxide
• rely more heavily on crops

That said, the sustainable diet laid out by this commission doesn’t call for a complete elimination of animal products. Instead, it recommends limiting your intake to the following amounts per week (3):

• Red meat: 3.5 ounces (100 grams)
• Poultry: 7.1 ounces (200 grams)
• Fish: 6.9 ounces (200 grams)
• Dairy: 61.6 ounces (1.8 liters)

Other reports include similar guidelines, such as flexitarian diets that are mostly plant-based but allow for small amounts of animal foods (7).

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An eco-friendly, sustainable diet ought to focus on plant foods. That’s not to say that you can’t eat any meat — you should just limit your intake to small amounts per week.

Although experts agree that cutting back on meat intake is crucial for sustainability, switching to a plant-based diet isn’t an environmental cure-all.

Firstly, the farm system is far from perfect. Industrial agriculture, which focuses on minimizing costs, is known to degrade soil health, harm human health due to mass pesticide use, and contaminate water and soil (8).

What’s more, large, industrial farms account for only 1% of the world’s farms but occupy 65% of its agricultural land (8).

This means that large farms have control over the market, making it difficult or impossible for small farms — which often use more sustainable practices — to compete (8).

Thus, making your diet more plant-based doesn’t necessarily make it more sustainable.

That’s why you should pay attention to factors like where your food is grown and its seasonality — as well as why supporting local farmers, when you’re able, is so important.

What about plant-based meat?

The sustainability of plant-based meats is complex.

A report sponsored by Beyond Meat states that plant-based meat generates 90% fewer greenhouse gas emissions, has 93% less effect on land use, and requires 46% less energy than U.S.-grown beef (9).

However, the numbers used to create these statistics don’t differentiate between beef raised in industrial feedlots and beef raised using regenerative, sustainable practices like intensive grazing management, which can improve soil health and preserve biodiversity (10).

Plus, research on the environmental impact of plant-based meat is often funded by the companies that manufacture the product.

Experts also point out that while popular plant-based beef alternatives are lower in saturated fat and cholesterol than beef, they’re higher in sodium. The U.S. Department of Agriculture (USDA) recommends limiting your sodium intake to reduce your risk of heart disease (11, 12).

Since there’s no long-term research on how plant-based meat affects health, it’s impossible to say that these alternatives are better for your health than beef or other meats.

Ultimately, a sustainable diet is one that limits highly processed foods, including plant-based meat (3).

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Going plant-based doesn’t automatically make your diet sustainable. You should also try to limit your processed food intake, support local farms, and learn about foods native to your area.

The following tips will help you follow an eco-friendly diet.

1. Aim to get most of your protein from plants

If you currently get most of your protein from animal sources, focus on cutting back gradually.

For sustainability, experts recommend eating at least 4.4 ounces (125 grams) of dry beans, lentils, peas, legumes, or nuts per day and no more than 1 serving of dairy and 1 serving of poultry, fish, eggs, or red meat per day (3, 7).

2. Eat more plants and fewer animal products

Focus on fruits, vegetables, nuts, legumes, and whole grains. Cut back on meat, poultry, fish, eggs, and dairy products (3).

3. Shop for foods that are sustainably produced

Look for foods that are produced using regenerative agriculture, which focuses on keeping soil healthy and thus supporting the entire ecosystem around the farm.

These farms tend to avoid harmful pesticides and fertilizers, as well as rotate crops so that soil nutrients don’t become depleted (13).

Products with the USDA’s organic label abide by several criteria that promote sustainability, but the label isn’t a guarantee. Likewise, small producers may not be organic-certified but may still abide by regenerative practices (3, 14).

At farmers markets, many farmers will answer questions about their farming practices.

4. Cook more

Oftentimes, food cooked at home is more nutritious than food purchased at a restaurant or fast-food chain. Cooking also cuts down on the resources and labor required for food production (3).

5. Reduce food waste

An estimated 30–40% of food in the U.S. food supply gets thrown away. While some waste is inevitable, minimizing food waste is vital for sustainability (3, 15).

Aim to cook and eat food before it spoils, use as much of the edible portion of produce as possible, eat your leftovers, and even find new ways to use scraps.

Sustainability is complex, and it’s not just a matter of eating less meat or buying all organic. A truly sustainable diet is both nutritious and environmentally friendly.

It’s not all about personal choices. Creating a sustainable food system means that policymakers and industries must change farming practices, the food supply chain, and more. Still, that’s not to say that your choices don’t matter or that there’s nothing you can do.

To be more eco-friendly right now, focus on eating more plants, buying from farms with good sustainability practices, and minimizing your own food waste.