How Does Your Diet Impact the Environment?

by Matt Durkin
MSc Nutrition Specialist
22/07/2020

One of the big topics recently is how our diet impacts the environment and our ‘carbon footprint’. But what does the current evidence say and how can we eat nutritiously while maintaining the equilibrium of the planet? 

The EAT-Lancet Study 

Background

In 2019, 37 nutrition experts from some of the most prestigious universities in the world collaborated to try and shed light on an emerging issue. By 2050 it is predicted that the world’s population will surpass 10 billion, and with our current diets we would be unable to feed this number of people. Therefore the scientists wanted to provide a number of recommendations on how we should change our eating patterns to something more sustainable. 

At the same time, this study highlighted the differing nutrition issues around the world. In more developed countries, ‘over-nutrition’ is a problem, as much of the population are consuming too many calories and consequently damaging their health. On the other hand, malnutrition is a problem is less developed parts of the world.  As you can appreciate, ensuring the whole world has access to the right amount of nutritious food is a critically important but highly complex topic.

Recommendations 

Based on numerous factors such as land and water requirements, emissions and other resources, the scientists provided dietary recommendations that will be sustainable for the planet while meeting the nutritional requirements of the world’s population. 

The researchers recommend that we need to be mainly consuming a plant-based diet, with most of our calories coming from wholegrains (232g per day), legumes (75g per day), nuts (50g per day) and starchy vegetables like potatoes (50g per day). The recommended diet would also include plenty of fruit (200g per day) and vegetables (300g daily). This doesn’t seem too radical as it largely mirrors what is recommended by most national health services like the UK’s Eatwell Plate. 

Where the diet has attracted criticism is with their recommendations for animal-based foods. The proposed ‘planetary diet’ suggests that we only consume on average 14g of red meat, 29g of poultry or 28g of fish per day. This would equate to around 1 burger, 2 chicken breasts or 2 portions of fish per week. Furthermore, eggs would be around one per week whereas 250g of dairy (about a glass of milk) would be a daily serving. The diet also has room for 31g of sugar and 50g of oils like olive oil. 

Support & Criticism

Unsurprisingly, this scientific paper was reported by media outlets world-over and gained equal measures of support and criticism. 

Support

Many of us recognise that some of our activities and lifestyles are damaging the environment and are unsustainable in their current format. Food production, for example, accounts for 26% of global greenhouse gas emissions. Worryingly, we also waste around 1 billion tonnes of food per year, which is a third of the food we produce. This is accounted for by food spoiling, food lost in supply chains and the food wasted by retailers, restaurants and consumers. In total, it is estimated that we waste 25% of the calories produced and this accounts for 6% of the world emissions. 

If these statistics weren’t harrowing enough, the UN Food and Agriculture Organisation has stated than in 2019, 820 million people went hungry and a third of the world’s population had one or more micronutrient deficiencies. Clearly we must do better.

Many people have also embraced dietary changes in recent years and an obvious example is the rise in vegetarianism and veganism. In the UK between 2014 and 2019, the amount of people who are vegan has increased 4-fold. A key reason for this lifestyle change is because of evidence showing how much of the world’s resources are needed to produce meat and other animal-based foods. 

Not only are we using half of the world’s habitable land for agriculture, we are also using 70% of our total fresh water. Ideally, we would be maximising these resources by producing and eating food that is nutritious but doesn’t require disproportionate amounts of land and water. In reality, this isn’t the case. Of the land we use for agriculture, 77% is for livestock. But these animals only provide 18% of our calorie requirements and 37% of our protein needs. It also requires 112 litres of water for every 1 gram of protein from beef, almost 10 times the amount needed for a gram of protein from legumes. 

However, people aren’t just choosing veganism because of environmental or ethical factors. There is a vast amount of scientific evidence showing how effective a whole food, plant-based diet is for health. Specifically, this eating pattern has been shown to effectively reduce body fat, blood pressure, LDL cholesterol and inflammation to name a few. It is also one of few diets that have been shown to put type 2 diabetes into remission and the only diet shown to reverse atherosclerosis – the narrowing of the arteries which is a hallmark of heart disease. 

Conversely, diets high in red meat have been linked to an increased prevalence of heart disease, cancer and type 2 diabetes. As red meat is plentiful in the western diet, it is becoming increasingly accepted that this is a contributing factor to many of the diet-induced diseases in developed countries. As we are easily surpassing our protein requirements and can get vitamins and minerals from other food sources eating meat daily or in some cases multiple times a day is just not necessary. 

The EAT-Lancet study has also received praise for highlighting the current environmental food issues and pulling all the factors together and then using these to make recommendations. Because of agriculture’s contributing role in climate change, it’s important that it receives coverage just like the other factors do. By raising awareness of the issue and resonating with people world-over, this is one of the first steps in creating a positive change. 

Criticism 

As you can imagine, this study invoked an emotive response from a lot of people and not all of this was positive. 

Some experts have rightfully said that a one-size-fits-all approach to nutrition is too simplistic and not optimal for a lot of people across the world. For example, it doesn’t take into account allergies or intolerances, which would mean a diet high in nuts or soy may not be possible for a lot of people. Furthermore, many people in the world do not possess the lactase enzyme to digest lactose, the sugar found in dairy. 

Certain nutritionists have also claimed that the recommended diet could lead to nutritional deficiencies such as iron, zinc, vitamin B12 and vitamin D. It is true that meat, eggs and dairy are nutrient dense and it can be more difficult to meet nutritional requirements without these in our diets. In many instances, supplementation or the regular consumption of fortified foods is required. 

That being said, nutritional deficiencies are rife in the western world with our current diets. Many women have low levels of iron, certain individuals struggle to absorb B12 efficiently, meaning supplementation or injections are necessary. Furthermore, everyone is recommended to take a vitamin D supplement through the winter months. Not only does this show that a one-size-fits-all approach isn’t to be recommended, it shows that our current diets leave a lot of room for improvement and we need to be open minded about changing for the better. 

Unsurprisingly, farmers and those that work in agriculture have questioned the EAT-Lancet report. They have criticised the report for being too simplistic by failing to account for local climate differences. For example, some land is not suitable for growing plant-based foods and can instead be used for grassland to feed cattle. The National Farmers Union claim the UK is ideal for rearing cattle as 65% of our farmland is more suited to grassland than growing other crops. Although this will still require a lot of water and the animals will still produce methane, it will be much more sustainable than chopping down trees to make room to grow animal feed like they are doing in the Amazon. 

Another factor that cannot be underestimated is how these new recommendations go against cultural and traditional eating habits. Meat, fish eggs and dairy have been consumed by humans for millennia and have been integral to our evolution. Because of this, these foods are that engrained in our society that a significant shift away from them will be challenging to say the least. That being said, the Coronavirus pandemic is the perfect example of how quickly the world can adapt to a ‘new normal’ in the wake of a global emergency. 

Summary

The EAT-Lancet study and their recommendations has certainly got the world talking about the environmental impact of nutrition, something which most will agree is a positive step. Although it has received its fair share of criticism as well as support, it is clear that we all need to do our bit to look after the planet. It is becoming increasingly clear that we will all need to embrace technological advancements as well as being open-minded towards lifestyle modifications. Although this early research has its flaws, it seems set to be built upon in the coming years as the world pulls together to create a more sustainable future. 

---

Sources
http://academiacienciasfarmaceuticas.cl/wp-content/uploads/2019/01/The-Lancet.pdf
https://science.sciencemag.org/content/360/6392/987
http://www.fao.org/state-of-food-security-nutrition/en/
https://www.vegansociety.com/news/media/statistics
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1466-8238.2010.00540.x
https://link.springer.com/article/10.1007/s10021-011-9517-8
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742661/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5466941/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5466936/
 

view all articles