Meat consumption equivalent to less than two chicken breast fillets per week can be considered sustainable for the planet, a new study estimates.
Researchers have been calling for reducing meat consumption and increasing legume intake to meet one’s protein needs for years now as livestock is estimated to be responsible for nearly 15 per cent of the global greenhouse gas emissions.
They have been urging people to adopt a plant-based “flexitarian” diet in which meat is eaten less than once a week.
But how exactly much meat consumption is recommended weekly has remained unclear. “Most people now realise that we should eat less meat for both environmental and health reasons. But it is hard to relate to how much ‘less’ is and whether it really makes a difference in the big picture,” said Caroline Gebara, an expert in sustainable development from the Technical University of Denmark.
The latest study, published in the journal Nature Food, puts this number at about 255 grams, or 9 ounces, of meat per week.
“We have calculated a concrete figure – 255 grams of poultry or pork a week – which you can actually visualise and consider when you are standing in the supermarket,” Dr Gebara said.
This is equivalent to about two chicken breast fillets, the limit of meat one person can consume weekly without harming the planet.
The figure applies only to poultry and pork. The study warns that even a “modest consumption” of beef exceeds what the planet can sustain.
“Our calculations show that even moderate amounts of red meat in one’s diet are incompatible with what the planet can regenerate of resources based on the environmental factors we looked at in the study,” Dr Gebara said.
“However, there are many other diets, including ones with meat, that are both healthy and sustainable.”
The study calls for better political guidance and public frameworks to support sustainable food choices.
The study considers environmental factors like carbon dioxide emissions, water and land use as well as the health impact of different diets.
It examines over 100,000 variations of 11 types of diets and calculates their respective environmental and health effects. It concludes that even moderate amounts of red meat exceeded planetary sustainability limits.
A pescetarian, vegetarian or vegan diet, on the other hand, is much more likely to be within the limits of what the planet can support, the study says.
Mixed diets such as vegetarian, but with the addition of dairy or eggs, can also be sustainable. “For example, our calculations show that it is possible to eat cheese if that is important to you, while at the same time having a healthy and climate-friendly diet,” Dr Gebara said. “The same is true for eggs, fish, and white meat but the premise is of course, that the rest of your diet is then relatively healthy and sustainable. But it doesn’t have to be either-or.”
