Carbon Footprint and Nutrition Styles

Food systems include all activities that carry foods from the field/farm to our tables. This includes how food is produced, processed, handled, marketed, and consumed. Research conducted in recent years show that what we eat has a great impact on the planet. A study supported by the United Nations in 2021 revealed that 34% of greenhouse gas emissions originates from food system.​

More than half of carbon emissions of food systems originates from high demand for meat and dairy products. Moreover, industrial agriculture which is highly dependent on fossil fuels also contributes to these emissions. This causes significant environmental problems due to extreme water usage, soil erosion and chemical substance utilization. Especially the production of animal products causes emissions of strong greenhouse gases such as methane and nitrous oxide.

Inequalities in the food system are directly linked to bad diets and health. Today, many people across the world cannot access healthy foods or are unable to afford these. More than 2 billion people face food and nutrition insecurity while 820 million people are undernourished.

And climate change is projected to deepen these problems even more. In addition, the 6th Assessment Report of Intergovernmental Panel on Climate Change (IPCC) indicates that increasing levels of CO2 in the atmosphere will decrease nutritional quality of our food. This includes protein, iron, zinc, and some vitamins contained in grains, fruits, and vegetables. In other words, even more people will be under the risk of micro nutritional deficiency without these critical nutrients.

Discussions have been going on for some time about the impacts of decreasing the consumption of meat and dairy products and vegetarian or vegan dietary habits on the climate crisis. Food choices play a critical role for the ones who wish to contribute less to climate change.

Today, food choices present a challenging process. Factors such as fair and good agriculture and healthy nutrition determine our choices. Moreover, our nutrition styles have a significant impact on our carbon footprint. And there is a new study conducted at Tulane University that draws attention in this subject:

In this study six popular nutrition types have been compared in terms of both their food qualities and their environmental impacts. Researchers have compiled nutrition quality scores by using data from over 16,000 adult diets in the United States of America. They have evaluated popular diet types such as Vegan, Vegetarian, Pescatarian, Paleo and Keto.

So, which one of these different nutrition types ‘won’? Let’s review our nutrition styles and the impact of popular diets on our carbon footprints!​

Keto and Paleo Style Nutrition

Most of us now know that red meat has a high level of carbon footprint. Therefore, it may not be surprising that keto and paleo diets which are based on meat products are listed as the least sustainable diets among the six diets that have been analyzed. In addition, it is again not surprising that these diets received the lowest score in terms of nutritional value.

As Andrew J. Yawn from Tulane has indicated in the press release regarding the study: “The keto diet, which prioritizes high amounts of fat and low amounts of carbs, was estimated to generate almost 3 kg of carbon dioxide for every 1,000 calories consumed. The paleo diet, which eschews grains and beans in favor of meats, nuts, and vegetables, received the next lowest diet quality score and also had a high carbon footprint, at 2.6 kg of carbon dioxide per 1,000 calories.”

Vegan, Vegetarian and Pescatarian Nutrition

Vegan diet has the least amount of carbon footprint with less than one quarter of the impact compared to keto diet thanks to 0.7 kg carbon dioxide for every 1,000 calories consumed.

Vegetarian diets follow vegan diets in terms of least carbon footprint levels, and they are followed by pescatarian diets. However, pescatarian diet receives the highest score in terms of nutrition quality from a health perspective. Pescatarian diets are followed by vegetarian and vegan diets in terms of human health.

More Trees, Less Cows for Climate

Among six diets, there is also a general omnivore diet which was represented by 86% of survey participants. Omnivore diets include both herbivore and carnivore diets. This type of nutrition style is positioned right in the middle in terms of sustainability.

Moreover, the plant-based Mediterranean diet which is hidden in the omnivore category is among the winners. Mediterranean diet is a nutrition type that stays away from fatty read meats by predominantly including local and seasonal vegetables. People nourished with this style of diet are observed to have improved carbon footprint and nutritional quality. Especially eating local and seasonal foods is the most efficient thing to do to reduce carbon footprint!

In short, you do not need to be vegan to reduce your carbon footprint. Tulane Study supports this fact. The researchers have proven that one third of omnivores eating vegetarian in any given day would be equal to eliminating 340 million passenger vehicle kilometers on average. In simple terms, you can contribute greatly to the planet by decreasing your meat consumption just a little bit.

Now we have no doubt that meat, especially red meat, has a high level of carbon footprint. Bovine meat is responsible for 8 to 10 times of emissions compared to chicken production and 20 times of legume production. Today many people are interested in transitioning to a plant-based diet. The study also shows that complete elimination of meat from our diets is a way to improve our health and reduce our carbon footprint.

We Can Replace Half of Meat and Dairy Products with Plant-based Alternatives

According to the study, replacing 50% of animal products with plant-based products can have a significant impact on the natural environment. One of the biggest illusions about living a more sustainable life is that it is about all or nothing.

People who defend the planet act with a feeling of emergency, however this emergency commonly emerges as “I will not ever travel with airlines, I will transition to zero waste immediately, I will quit eating meat.” But the situation does not have to include an all or nothing mindset, and only decreasing certain behaviors can be enough to make some progress.

Let’s Talk About Reducing Meat Instead of Completely Eliminating It

A study published in Nature Communications magazine showed that replacing animal products (pork meat, chicken, beef and milk) by 50% with plant-based alternatives can “decrease global emissions originating from agriculture by 31%, save forests and improve nourishment of millions of people”.

The researchers show that additional benefits can be gained in terms of climate change and biodiversity thanks to reforestation of the lands no longer needed by husbandry after meat and dairy products are replaced with plant-based alternatives.

Positive Impacts of Nutritional Change on Climate Crisis

Although global food supply constitutes less than 20% of energy supply, animal-based foods are responsible for most of the negative impacts on land usage, water usage, biodiversity, and greenhouse gas emissions in global food systems.

In short, the positive impacts that can be experienced by 2050 can be listed as follows if only individuals reduce their animal product consumptions;

1. Global agricultural fields would decrease by 12% instead of expanding.
2. Reduction in forests and other natural areas would almost completely stop.
3. Nitrogen input in agricultural fields would be almost half of the projections.
4. Water usage would decrease by 10%.
5. Greenhouse gas emissions can be reduced by 31% by 2050 due to carbon accumulation in the protected lands.
6. Malnourishment would decrease to 3.6% globally compared to the 3.8% in the reference scenario and the number of malnourished people would decrease by 31 million.

It has become obvious that promoting diets containing low levels of animal-based food is a critical component in reaching targets to reduce climate change, reaching health and food security targets across the world, and keeping natural resource usage in line with the limits of the planet.

Carbon Footprint and The Importance of Nutrition

In short, the intersection between carbon footprint and nutrition shows that our preferences in understanding sustainable life play a significant role in terms of environmental impacts. The study comparing different diet styles emphasizes not only the nutritional values of these, but also their ecological footprints. Diets based on animal products such as keto and paleo are not only listed at low ranks in terms of nutritional value, but they are observed to cause an increase in carbon emissions. On the other hand, certain plant-based diets such as vegan diet are not only environment-friendly, but also offer significant health benefits.