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Masses of burgers, steaks, cheese and lots of eggs: Americans love their animal products. But researcher Oliver Taherzadeh found that only a relatively small group of heavy consumers need to change their diet to achieve a huge environmental gain.

The day we exhausted all the biological resources the Earth can regenerate in a year, Earth Overshoot Day, was July 28 this year. For the Dutch it would be April 12 and for the Americans March 13. Americans have the largest ecological footprint in terms of food consumption; if they consumed more plant products and less animal products, the impact on the environment could be significantly reduced. Taherzadeh is assistant professor at the Institute of Environmental Sciences; he studied the impact that American households could have by changing their eating habits.

Smart switch to sustainable food

“I looked at a representative group of over 7,000 Americans and what they eat daily, and assessed the environmental outcomes of their transition to the EAT-Lancet diet,” says Taherzadeh. In this diet, the main emphasis is on plant-based foods and a low intake of animal products, especially dairy products and red meat.

“We modeled realistic dietary changes in the scenarios, assuming that people who eat a lot of meat would reduce their meat intake in moderation. I also calculated the environmental impact of the different meals and the individual raw materials they contain. If you eat a pizza with peperoni, you consume a certain amount of pork, but there are also the tomatoes in the sauce and the wheat in the dough. Each of these products has a different ecological footprint.

The EAT-Lancet Diet

The study looked at a partial transition to the EAT-Lancet diet. This diet, compiled by 37 independent international scientists, not only contains plenty of plant-based foods, but also leaves room for animal products. The diet was proposed to enable all 10 billion people to be able to eat healthily and sustainably by 2050.

A remarkable finding from the study is that not all Americans need to change their diet to achieve significant reductions in the climate and land impacts of the US food system. We could achieve the same environmental gains if the EAT-Lancet diet were adopted by the 20% of high-impact consumers, as we could see if the remaining 80% of the American population did the same. The greenhouse gases and land footprint of the US food system could be more than halved if this group partially adopted the EAT-Lancet diet.

Eating habits

Contrary to what people may think, there is considerable variation in eating habits in the United States. Taherzadeh: “In many cases, we look at a national average of eating habits when formulating policies for sustainable eating habits. But that ignores the huge differences in dietary habits of individuals and groups within countries. These unique eating habits become visible when you distinguish between different income groups, genders and ethnic backgrounds. I created profiles for the impact of different groups by looking at individual household members and what they eat. This will help policy makers encourage behavior change where it is most needed.

“By introducing targeted measures, not to blame people but to encourage them to change their behavior, we can reduce the impact of food on the environment.”

Encourage behavior change

Taherzadeh believes the real task is now in the hands of governments and markets. “We cannot blame individuals. People are often locked into particular consumption patterns due to inequalities, such as lack of time, money or education.

“By introducing targeted measures, not to blame people but to motivate them to change their behavior, we can reduce the impact of food on the environment. For example, an effective measure in restaurants is to promote sustainable choices and make them cheaper. A meat tax would also be a good option. Where possible, we should consider subsidizing greener alternatives so that consumers are not penalized for making sustainable choices.

Dutch diet

Although he has only studied eating habits in the United States, Taherzadeh expects the study’s findings can also apply to the Dutch food system. “Even in the Netherlands there are huge differences in terms of eating habits, so I would expect to see the same trend. The Dutch diet isn’t unsustainable, but it’s high in meat and dairy. Targeted policy measures aimed at consumers could have a significant impact.

What can you do?

You can make an impact today by changing your diet. Oliver Taherzadeh has some tips for doing this relatively easily.

‘Do you eat meat and/or dairy every day? If so, try following a weekday plant-based diet. If you do this, you will reduce your consumption of animal products by 70%. Even substituting animal and plant proteins can significantly reduce the environmental footprint of your diet.

“Have you ever switched to a – partly – plant-based diet yourself? If so, you can try to encourage others to do the same, through your social networks, at work, and by joining social movements advocating for policy change.

“You can also become a prosumer and take control of the food system. Try growing food in your garden or on your balcony. If you don’t have a garden or a balcony, you can consider renting a housing estate (there are more than 240,000 in the Netherlands) or joining an agricultural collective. In addition to saving money, growing your own food is proven to improve mental and physical health.

The need for an overhaul of the food system

While adopting a plant-based diet is crucial, Taherzadeh says the major problems we see in our food system (overconsumption, food waste, loss of biodiversity and malnutrition) are symptoms of our endless pursuit of economic growth. In a new perspective article in Nature Sustainability, more than 30 authors (including Taherzadeh) propose a plan for an alternative food system. This system is designed not by the logic of growth, but by principles of sufficiency, regeneration, distribution and care.

Text: Lisanne Bos