By Jessica Sansom, RNutr, Sustainability Director at Huel
When people talk about climate change, the images that most readily spring to mind are chimney stacks belching smoke, motorways clogged with vehicles, air travel, or perhaps a ticking energy meter. What most people don’t think about – food.
The impacts of food
Our food system contributes a staggering 26% of all global greenhouse gas emissions1, more than all forms of transport combined. For individuals living in developed countries, what we eat is often the largest contributor to our carbon footprints – yet it is so often overlooked in the actions we can take to tackle climate change.
The impacts of food also extend far beyond climate change. Food production is the leading cause of deforestation, land use change, and biodiversity loss; is responsible for 70% of all freshwater use; and is the leading source of water pollution.1
Figure 1: The Environmental Impacts of Food and Agriculture
Where in the food chain does the impact occur?
Whilst the whole food system (from farming through to transport, cooking and waste disposal) causes these issues, the greatest impacts occur in the agricultural stage, particularly from livestock.1 The production of meat, eggs, and dairy products contributes 14.5% of total global greenhouse gas emissions and uses 70% of agricultural land.1 The grazing of livestock and the production of feed crops are together the primary drivers of deforestation, biodiversity loss, and land degradation.2
Aren’t food miles the real problem?
Food miles was a term coined in the 1990s by Dr Professor Tim Lang, a professor of food policy at London’s City University. It was created to demonstrate some of the hidden impacts of food to consumers in a simple way. It garnered a lot of attention, but its singular focus also caused issues. Food miles are important to consider, but in most cases, they are not the largest contributor to the carbon footprint of food.
As mentioned earlier, most (around 80%) greenhouse gas emissions from food come from the agricultural stage – either in the clearance of land for grazing or crop production or on-farm activities such as the application of agro-chemicals such as fertilisers or methane emissions from livestock or manure.
For most food products, transport actually only accounts for less than 10% of the carbon footprint.1 The exception to this is food that is transported by air. Thankfully the amount of food air freighted is very low – of all transport-related emissions from food, only 0.02% comes from air freight.4 It is simply too expensive to be a standard mode of transport. However, when it is used the impacts are significant – with airfreight having a carbon footprint that is around 50 times more than sea freight. So it is good to keep an eye out for labels that indicate a food product has travelled by air – typically highly perishable foods such as berries or green beans.
The food waste mountain
What does result in more carbon emissions than transport, is the mind-boggling amount of food that is wasted each year. It is estimated that one-third of all food produced each year for human consumption is wasted.5 This happens both before it reaches us – during harvest, storage and transportation – and also once it has reached supermarkets and been sold. Food wastage before it reaches a market tends to occur more often in low-income countries. In developed countries, more than 60% of food waste happens in the home, with the average person in the UK wasting 30 kilograms of food per year.6
The environmental impact of this waste is substantial. When food is wasted, ALL the resources required to produce that food – water, land, fuel, fertilisers, and so on – are also wasted. Throwing away a bruised apple is equivalent to pouring 125 litres of water down the drain.7
If food waste were a country, it would be the third largest greenhouse gas emitter after the United States and China, accounting for 6% of total global emissions.8
6 easy ways you can reduce food waste
What are low-carbon foods?
Plants. Per unit of weight, serving, energy, and protein weight – plant-based foods have been shown to have a lower carbon footprint than animal-sourced foods. This is also true for land use, energy use, and water pollution.9
Put simply, grains, fruit, and vegetables have the lowest environmental impacts per serving whilst meat from animals such as cows, sheep, and goats have the highest impact per serving.
Vegan and vegetarian diets provide the greatest reductions in greenhouse gas emissions10 and land use with vegetarian diets having the greatest reductions in water use.11 Switching from red meat (regardless of quantity consumed) to fish, poultry, and pork also reduces environmental impacts, though this is to a lesser extent than switching to plant-based alternatives.13
A fully plant-based diet can cut the use of agricultural land by 75%.13 Land that is no longer required for food production could help to remove vast quantities of carbon dioxide from the atmosphere each year as natural vegetation is reestablished and soil carbon re-accumulates. A reduction in land used for agriculture would also result in improved biodiversity and the re-establishment of habitats for endangered species.
Low-carbon diets also have health benefits
What’s good for the planet, also happens to be really good for our health too. Increasing scientific consensus suggests that a diet that is rich in plant-based foods and contains fewer foods from animal sources is significantly more beneficial for our health.14
Plant-rich diets are associated with:
| Reduced inflammation15 | Reduced risk of heart disease and stroke16,17 |
| Reduced blood cholesterol18 | Good gut health / diverse gut microbiota19 |
| Reduced risk of cancer20 | Reduced obesity / lower BMI21 |
Of course not all plant-based diets are healthy. It is important that consideration is given to the types and quality of the plant foods concerned. Refined grains, and sugar-sweetened beverages, snacks, and confectionery are foods that can still be considered “plant-based” as they or their ingredients originate from plants and may be free from animal products but they are classed as high in fat, sugar, and salt (HFSS).
What is the ideal diet for our own health and the planet?
Let’s face it, what we eat is driven by many many different factors. It can be influenced by culture, religion, and personal preference; access to certain foods and financial constraints play a major role; and of course time.
So it is not particularly helpful to talk about an ideal diet or to be too restrictive about what can and cannot be included. The best advice we can offer is to adopt a plant-rich diet. This consists of foods derived from plants including vegetables, grains, legumes, nuts, seeds, fruit, and meat alternatives with modest consumption of meat, fish, eggs, and dairy products.
Individuals should preferably choose minimally processed foods and drinks: whole grains over refined grains; whole fruits over fruit juices; unrefined non-tropical vegetable oils (rich in mono- and polyunsaturated fatty acids) such as olive and sunflower oil over coconut oil and partially hydrogenated oils; and unsweetened beverages such as water, coffee or tea over fizzy drinks and other sugar-sweetened beverages.
Well-planned plant-rich diets can offer all the necessary protein, fats, carbohydrates, vitamins, and minerals for optimal health, and are often higher in fibre and phytonutrients. However, vegans may need to add a supplement (specifically vitamin B12) to ensure they receive all the nutrients required.
For people who are new to plant-rich diets and who currently eat animal products frequently, it might be easier to make a gradual shift by adopting ‘plant-forward’ eating, where meat is not excluded, but is not the central feature of the meal. Gradual reductions are much easier than highly restrictive diets, and they also allow for religious and culturally appropriate forms of a plant-rich diet.
Figure 2: The Planetary Health Diet
The planetary health diet (shown above) is a flexitarian diet created by the EAT-Lancet commission as part of a report released in The Lancet in 2019. The aim of the report and the diet was to address the following goals:
- To feed a world population of 10 billion people in 2050
- To greatly reduce the worldwide number of deaths caused by poor diet
- To be environmentally sustainable as to prevent the collapse of the natural world
Eating for the future
It’s easy to feel powerless in relation to climate change. To believe that as individuals, there is little we can do to stop the use of fossil fuels and change energy systems, to change the policies and practices of governments or large companies. The reality though is that we can all make a significant contribution to climate change – at every meal, every day. With the massive bonus of improving our own health at the same time. Why not start today?
Disclaimer: This blog has been written in collaboration with the nutrition team at Huel UK and reviewed by the MyNutriWeb nutrition and dietetic team. Approval of each sponsor and activity is carefully assessed for suitability on a case by case basis. Sponsorship does not imply any endorsement of the brand by MyNutriWeb, its organisers, its moderators or any participating healthcare professional, or their association. Sponsorship funds are reinvested into the creation and promotion of professional development opportunities on MyNutriWeb.
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References
[1] Poore, J., & Nemecek, T. (2018). Reducing food’s environmental impacts through producers and consumers. Science, 360(6392), 987-992.
[2] FAO (2017). Livestock solutions for climate change.
[3] FAO. (2011). The state of the world’s land and water resources for food and agriculture
[4] UNEP-WCMC & IUCN, Protected Planet Report 2020 (2021)
[5] Searchinger, T. et al. (2018). Creating a Sustainable Food Future—A Menu of Solutions to Feed Nearly 10 Billion People by 2050. World Resources Institute.
[6] World Resources Institute. Reducing Food Loss and Waste: Setting a Global Agenda. Washington DC, USA: WRI 2016
[7] Mekonnen MM and HOekstra AY. The green, blue, and grey water footprint of crops and derived crop products. Hydrology and Earth System Sciences. 2011; 15(5): 1577-1600
[8] World Resource Institute’s CAIT Climate Data Explorer
[9] Food in the Anthropocene: the EAT-Lancet Commission on healthy diets from sustainable food systems. Lancet 2019; Issue 10170, 393: 447-92
[10] Tilman D, Clark M. Global diets link environmental sustainability and human health. Nature 2014; 515: 518-22
[11] Vanham D et al. The water footprint of different diets within European sub-national geographic entities. Nature Sustainability. 2018; 1(9): 518-25
[12] Aleksandrowicz L, Green R, Joy EJ, Smith p, Haines A. The impacts of dietary change on greenhouse gas emissions, land use, water use and health: a systematic review. PLoS One 2016; 11: e0165797
[13] Ritchie, H. Food production is responsible for one-quarter of the world’s greenhouse gas emissions. Our World in Data. 2019.
[14] Willett et al. 2019. Food in the Anthropocene: the EAT-Lancet Commission on healthy diets from sustainable food systems.
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[16] Perez-Cornago A, Crowe FL, Appleby PN, Bradbury KE, Wood AM, Jakobsen MU et al. Plant foods, dietary fibre and risk of ischaemic heart disease in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Int J Epidemiol. 2021;50(1):212–22.
[17] Tong TYN, Appleby PN, Key TJ, Dahm CC, Overvad K, Olsen A et al. The associations of major foods and fibre with risks of ischaemic and haemorrhagic stroke: a prospective study of 418 329 participants in the EPIC cohort across nine European countries. Eur Heart J. 2020;41(28):2632– 40.
[18] Bergeron N et al. Effects of red meat, white meat and nonmeat protein sources on atherogenic lipoprotein measures in the context of low compared with high saturated fat intake: a randomised controlled trial. The American Journal of clinical nutrition. 2019: 110(1)24-33
[19] Tomova A et al. The Effects of Vegetarian and Vegan Diets on Gut MIcrobiota. Frontiers in Nutrition. 2019: 6(47)
[20] Segovia-Siapco G, Sabaté J. Health and sustainability outcomes of vegetarian dietary patterns: a revisit of the EPIC-Oxford and the Adventist Health Study-2 cohorts. Eur J Clin Nutr. 2019;72(Suppl 1):60–70
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