Is CO₂ the main "ingredient" in your diet?

Since climate change emerged years ago as the greatest challenge faced by humanity, people all over the world have mobilised to make a difference and to adopt a more sustainable lifestyle. Even so, in the UK alone, the average annual carbon footprint per person is about 10 tonnes CO2 (27 Kg per day), double the world average.

Food on its own causes 20-30% of all global greenhouse gas, GHG, emissions. Meat consumption is responsible for much higher emissions than plant-based food. But then again, not all meats have the same impact. Also, is it more sustainable to eat a vegan cake produced miles away and wrapped in protective packaging than a locally produced sausage roll?

What's the most sustainable diet?

Although, the list of available diets is much longer, we are focusing on those four that are most common. That is regular; vegetarian and semi vegetarian; vegan; and climatarian diets.

We use the term “Regular” diet to refer to a diet that combines a variety of ingredients from all the food groups, including all types of meat and fish. This diet is by far the least sustainable one, due mainly to three ingredients: beef, lamb, and goat, as they cause almost seven times more GHG emissions than any other animal-based foods.

Beef, lamb and goat meat – least sustainable meals

Grazing animals have a significantly higher climate impact than other livestock. The reason being that food ferments in their stomachs, so they burp methane gas. In addition, they use more land; need more energy intensive feed; and produce more manure -hence more methane emissions- than, let’s say, pigs or chickens. Consequently, a diet including meat and other derives from these animals will result into a much more intense GHG emissions per kg of food.

Vegetarian diets offer loads of options

Another very well-known diet is the vegetarian diet, which includes all food groups except for meat and fish. One of the positive things about vegetarianism is that offers enough options to find one we feel good with. Some of the semi vegetarian variations are Pescetarianism, which rules out meat, but incorporates fish and seafood; or Pollotarianism that includes chicken.

In recent years, we have seen the raise of the flexitarian diet, which is essentially a vegetarian diet with the occasional meat dish from time to time.

The most sustainable of all the vegetarian options is the full vegetarian diet. Interestingly, a vegetarian diet which includes cheese is less climate friendly than a diet which leaves out cheese and includes chicken. This is because of the carbon footprint associated with cheese production.

Veganism, the queen in sustainable eating

Although the term Veganism was coined in the 1940s, it wasn’t until the late 2010s that Veganism became a worldwide trend, with The Economist declaring 2019 “the year of the vegan”. A vegan diet contains only plants and foods made from plants. There is also what is called a Whole Food Plant-Based Diet, WFPBD, which is essentially a vegan diet without any refined and processed food. There is no doubt that a completely plant-based diet has the lowest carbon impact of all the possible diets.

Climatarian diet, born to be sustainable

Finally, the Climatarian is the first diet created with the purpose of reducing carbon footprint. Designed in 2012 by a professor at the University of Aberdeen, eating a climatarian diet involves leaving off the menu: beef, lamb, goat, unsustainable fish, air flown food and heated greenhouse grown food. It’s believed that by doing that, you will cut your food CO₂e by 90%.