Sustainable diets

This HEART UK Nutrition Academy webpage has been funded by Novartis Pharmaceuticals UK Ltd who have had no input into the content or development of this material.

Sustainable diets are plant-based diets designed to limit the damage on the environment and human health. We take a thorough look into what they are and how they can benefit cardiovascular health.

Take home messages

Our food system has a sizeable impact on climate change and the environment. It significantly contributes to greenhouse gas (GHG) emissions, biodiversity loss, water use, land use, deforestation, soil and water pollution, and marine life depletion.
Adopting a more sustainable food system means prioritising a diet focused on healthy plant foods while minimising consumption of meat and animal products.
Sustainable diets are healthy plant-based diets with specific emphasis on:
- higher intakes of healthy plant foods
- plant proteins prioritised over animal proteins
- minimal intakes of meat and moderate intakes of dairy
- reducing food waste.
Sustainable diets are essential for both human and planetary health.
The food components and nutritional profile of sustainable diets are identifical to dietary patterns proven to positively impact on cardiovascular health.

Human & planetary health EAT Lancet Planetary Health Diet Sustainable diets: the what and why

1 Less meat 2 Plant proteins 3 Variety of plants 4 Whole grains 5 Fruit and veg 6 Less waste

Sustainable diets are gaining attention among health professionals and the public, driven by the unequivocal evidence demonstrating the effects of our food system on the environment^1–6.

There is widespread agreement among the global scientific community regarding the environmental challenges posed by our food system, including its impact on^1,7:

global warming
greenhouse gas (GHG) emissions
biodiversity loss
water pollution
soil degradation
excessive fertilizer use
loss of marine life.

Agriculture and fisheries have become pivotal in global and national environmental strategies to combat climate change and reverse biodiversity decline^4,8,9.

Sustainable diets balance human and planetary health

Sustainable diets, as defined jointly by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO), encompass various factors⁶:

“A sustainable diet should promote all dimensions of individuals’ health and wellbeing; have low environmental pressure and impact; are accessible, affordable, safe and equitable; and are culturally acceptable.” FAO & WHO 2019

This holistic definition is shared by prominent environmental bodies, including the Intergovernmental Panel on Climate Change (IPCC)⁴, World Wide Fund for Nature (WWF)¹⁵, EAT Forum¹² and the United Nations⁹.

Because of the common perception of sustainable diets primarily addressing environmental concerns, there's a tendency to overlook their equal emphasis on human health. In essence, a sustainable diet should:

optimise nutritional and health needs of different population groups
able to address both non-communicable diseases (obesity, cardiovascular disease, type 2 diabetes and some cancers) in middle-to-high income countries and hunger in low-income countries
minimise environmental burden, addressing GHG emissions, biodiversity, water use and pollution, and responsible fishing
be affordable, available, and accessible to all individuals
be adaptable to different cultural and religious preferences.

The sustainable reference diet

In 2019, the EAT Lancet commission, made up of 37 international scientists, developed the EAT Planetary Health Diet (EAT PHD). This is a "reference" diet that goes beyond general dietary advice and aims to set global targets for promoting healthy diets and sustainable food production¹².

The EAT PHD offers guidance on eight food groups, designed for an average adult with a daily caloric requirement of 2,500kcal. Each food group has a recommended daily amount with a broad range allowing for customisation to address different national needs: cultural, nutritional and environmental.

The EAT PHD recommendations

Food group

g per day

% caloric intake

Whole grains

Rice, wheat, corn etc.

232

32%

Tubers or starchy vegetables

Potatoes, yams, cassava etc.

50 (0-100)

Vegetables

Including dark green and orange

300 (200-600)

Fruit

200 (100-300)

Dairy milk or equivalent

250 (0-500)

Protein foods

Beef, lamb and pork
Chicken and other poultry
Eggs
Fish
Legumes (soya, beans, lentils, peanuts)
Nuts

14 (0-28)
29 (0-58)
13 (0-25)
28 (0-100)
100 (0-225)
25

1%
2%
1%
2%
17%
6%

Added fats

Unsaturated oils
Saturated oils

40 (20-80)
11.8 (0-11.8)

14%
4%

Added/free sugars

31 (0-31)

The EAT PHD is fully flexible. It includes small amounts of meat and animal products but is mainly based on healthy plant foods.

Similar plant-based dietary recommendations have been proposed by global and national organisations such as WWF¹⁵, IPCC¹⁹, British Dietetic Association’s One Blue Dot¹⁸, and the UK National Food Strategy¹.

EAT PHD impact on health and environment

Shifting the global population towards the EAT-PHD is projected to make substantial differences to human and planetary health, including^12,20:

19-24% fewer deaths, mainly due to reduced non-communicable diseases
42% reduction in GHG emissions, largely from limiting red meat intake to 100g to 200g per week, and limiting dairy to 250ml daily.
23.5% reduction in fertilizer use (nitrogen and phosphorus) which reduces soil degradation and loss of marine life
10% less water use.

Similar health and environmental benefits have been observed in other proposed sustainable, plant-based eating patterns^20–22.

Sustainable diets are good for human health and good for the planet

1. Minimise meat consumption

2. Prioritise plant proteins over animal proteins

3. Variety and diversity of plant foods

4. Whole grains

5. Fruit and vegetables

6. Less food waste

1. Minimise meat consumption – at the heart of the matter

Good for health

Eating less red meat (both processed and unprocessed) has been linked to reduced cardiovascular disease (CVD) and cancer risk, and improves lipid profiles²³.

More about meat and CVD

Good for the planet

Beef, lamb and cattle are by far the biggest dietary environmental burdens^{3,12,15,18,24}.

Farmed animals, especially cattle and sheep, are the primary cause of deforestation. They use over 70% of agricultural land, mainly for growing crops to produce animal feed. Redirecting crops for direct human consumption could significantly reduce land use and feed more people worldwide^12,17,25.
Animal farming accounts for the majority of dietary GHG emissions.^1,12,26
Conversion of wild land to farmland releases stored carbon into the atmosphere and removes the Earth’s natural ability to reabsorb carbon from the atmosphere. The net effect is more GHG in the atmosphere.
Animal farming is the single biggest driver of biodiversity loss^5,11

2. Prioritise plant proteins over animal proteins

Good for health

Plant proteins (legumes, nuts and seeds) offer a well-rounded nutritional profile, improving cardiovascular outcomes and blood lipid levels, especially when replacing meat in the diet²⁷.

Explore our plant-based diet review for a detailed examination of the evidence.

Good for the planet

Plant proteins have a far lower environmental burden than meat and other animal proteins^12,15,24.

Comparing the intake of 100g of protein from beans and lentils to an equivalent amount of protein from beef results in²⁴:

50 times fewer GHG emissions
23 times less land use, which is crucial for carbon absorption and improved soil quality
run-offs into oceans and freshwater 19-fold lower
16 times fewer acidifying emissions

Legumes act as natural fertilisers: legumes add nitrogen back to the soil, reducing the need for artificial fertilizers. This in turn decreases fertilizer runoff into waterways, helping to preserve marine life28–30.

3. Variety and diversity of plant foods

Good for health

Different plant foods provide different nutrients, so it’s important to eat a variety to achieve optimum nutrient intakes. For instance:

oats and barley are rich in beta-glucans which lower serum cholesterol
whole wheat's bulking fibres enhance gut transit and satiety
dark green vegetables offer iron and calcium
orange and red fruits and vegetables supply beta-carotene, an antioxidant.

Good for the planet

Currently, agriculture revolves around just five crops – soya (mainly for animal feed), wheat, rice, maize, and sugar cane – despite the existence of over 100,000 edible plant species.

This monoculture depletes soil of nutrients and biodiversity, escalating the demand for artificial fertilizers and adversely affecting soil quality, water absorption and crop yield^1,5,11. As different plants use different soil nutrients, growing a greater variety of crops at different times on the same land allows for soil nutrients to be restored.

4. Whole grains

Good for health

Substituting refined grains for whole grains is associated with improved cardiovascular disease outcomes, thanks to the superior nutrient quality of whole grains – richer in unsaturated fat, antioxidant vitamins and fibre³¹.

Find out more about whole grains.

Good for the planet

Whole grain foods generate less waste compared to refined grains, as they retain the outer bran layer and central germ. Choosing whole grain products over refined ones allows for greater food production with the same crop volume, reducing the use of fresh water, land and fertilisers. In practical terms, the same volume of wheat crops can be used to produce 42 loaves of white bread or 60 loaves of wholegrain bread32.

5. Fruit and vegetables

Good for health

Fruit and vegetables and their nutrients have been associated with improved blood lipid levels and reduced CVD risk³³.

Find out more in our plant-based diets article.

Good for planet

Like other plant foods, fruit and vegetables have a much lower environmental footprint than animal products²⁴. However, the footprint of fruit and vegetables varies significantly.

Low environmental footprint	High environmental footprint
Seasonal and field-grown fresh produce Canned and frozen Trucked or shipped	Out of season Not locally produced, requiring: air-freight transportation and/or use of heated greenhouses

6. Less waste

Good for health

The largest contributor to household food waste in middle to high-income countries is fruit and vegetables, mainly due to their high perishability³⁴. Foods high in fat, salt and/or sugars result in less waste. Eating all fruit and vegetables purchased can improve the cardiovascular-protective quality of a person’s diet and can potentially displace less healthy food options.

Good for the planet

Wasted crops lead to inefficient land and water use, along with unnecessary GHG emissions, biodiversity loss and the use of fertilisers^1,35. Notably, the most discarded food items are fruits and vegetables, which emit a potent GHG (methane) into the atmosphere as they decompose.

In summary

Our food system, particularly the farming of animals, contributes to the depletion of our planet's resources and imposes a substantial burden on the environment, contributing to climate change. Adopting a more sustainable food system means prioritising healthy plant foods while minimising meat and animal product consumption. This both supports cardiovascular health and mitigates multiple environmental burdens, including GHG emissions, land use change, biodiversity loss, water use, reduced soil quality and loss of marine life. Consequently, adopting plant-based dietary patterns is essential for both human and planetary health.

Read our review on plant-based diets and cardiovascular health

References

Dimbleby H. The National Food Strategy - The Plan. The National Food Strategy; 2022. Accessed August 14, 2023. https://www.nationalfoodstrategy.org/
Green R, Milner J, Dangour AD, et al. The potential to reduce greenhouse gas emissions in the UK through healthy and realistic dietary change. Climatic Change. 2015;129(1):253-265. doi:10.1007/s10584-015-1329-y
Scarborough P, Clark M, Cobiac L, et al. Vegans, vegetarians, fish-eaters and meat-eaters in the UK show discrepant environmental impacts. Nat Food. 2023;4(7):565-574. doi:10.1038/s43016-023-00795-w
Shukla PR, Skea J, Slade R, et al., eds. Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change.; 2022. doi:10.1017/9781009157926
Benton T, Bieg C, Harwatt H, Pudasaini R, Wellesley L. Food System Impacts on Biodiversity Loss: Three Levers for Food System Transformation in Support of Nature. Chatham House; 2021:75. Accessed June 9, 2023. https://www.chathamhouse.org/2021/02/food-system-impacts-biodiversity-loss
World Health Organisation, FAO. Sustainable Healthy Diets: Guiding Principles. WHO & FAO of the UN; 2019:37. Accessed June 9, 2023. https://www.who.int/publications-detail-redirect/9789241516648
Murakami K, Livingstone MBE. Greenhouse gas emissions of self-selected diets in the UK and their association with diet quality: is energy under-reporting a problem? Nutrition Journal. 2018;17(1):27. doi:10.1186/s12937-018-0338-x
DENSZ. UK’s Nationally Determined Contribution, updated September 2022. GOV.UK. Published September 23, 2022. Accessed August 9, 2023. https://www.gov.uk/government/publications/the-uks-nationally-determined-contribution-communication-to-the-unfccc
UN. The 17 Sustainable Development Goals. UN Department of Economic and Social Affairs & Sustainable Development. Published 2023. Accessed January 9, 2024. https://sdgs.un.org/goals
Crippa M, Solazzo E, Guizzardi D, Monforti-Ferrario F, Tubiello FN, Leip A. Food systems are responsible for a third of global anthropogenic GHG emissions. Nat Food. 2021;2(3):198-209. doi:10.1038/s43016-021-00225-9
Taylor A. Land of Plenty: A Nature-Positive Pathway to Decarbonise UK Agriculture and Land Use. WWF-UK; 2022:21.
Willett W, Rockström J, Loken B, et al. Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems: Supplementary Material page 40. The Lancet. 2019;393(10170):447-492. doi:10.1016/S0140-6736(18)31788-4
Ritchie H. Wild mammals make up only a few percent of the world’s mammals. Our World in Data. Published December 15, 2022. Accessed January 15, 2024. https://ourworldindata.org/wild-mammals-birds-biomass
BIOACID: Biological effects of ocean acidification. Accessed January 15, 2024. https://www.bioacid.de/
Halevy S, Trewern J. Eating for Net Zero Technical Report. WWF-UK; 2023:39. Accessed December 1, 2023. https://www.wwf.org.uk/eating-for-net-zero
WWF. Overfishing. World Wild Fund for Nature. Published 2023. Accessed January 15, 2024. https://www.worldwildlife.org/threats/overfishing
Ritchie H, Rosado P, Roser M. Environmental Impacts of Food Production. Our World in Data. Published online December 2, 2022. Accessed June 26, 2023. https://ourworldindata.org/environmental-impacts-of-food
Arens U, Convery L, Garton L, et al. One Blue Dot - the BDA’s Environmentally Sustainable Diet Project. BDA One Blue Dot. Published December 12, 2019. Accessed January 9, 2024. https://www.bda.uk.com/resource/one-blue-dot.html
Mbow C, Rosenzweig C, Barioni LG, et al. Chapter 5 : Food Security. In: Climate Change and Land: An IPCC Special Report on Climate Change, Desertification, Land Degradation, Sustainable Land Management, Food Security, and Greenhouse Gas Fluxes in Terrestrial Ecosystems.; 2019:114. Accessed January 15, 2024. https://www.ipcc.ch/srccl/chapter/chapter-5/
Springmann M, Spajic L, Clark MA, et al. The healthiness and sustainability of national and global food based dietary guidelines: modelling study. BMJ. Published online July 15, 2020:m2322. doi:10.1136/bmj.m2322
Aleksandrowicz L, Green R, Joy EJM, Smith P, Haines A. The Impacts of Dietary Change on Greenhouse Gas Emissions, Land Use, Water Use, and Health: A Systematic Review. Wiley AS, ed. PLoS ONE. 2016;11(11):e0165797. doi:10.1371/journal.pone.0165797
Scheelbeek P, Green R, Papier K, et al. Health impacts and environmental footprints of diets that meet the Eatwell Guide recommendations: analyses of multiple UK studies. BMJ Open. 2020;10(8):e037554. doi:10.1136/bmjopen-2020-037554
Al-Shaar L, Satija A, Wang DD, et al. Red meat intake and risk of coronary heart disease among US men: prospective cohort study. BMJ. Published online December 2, 2020:m4141. doi:10.1136/bmj.m4141
Poore J, Nemecek T. Reducing food’s environmental impacts through producers and consumers.; additional calculations for plant milks, milk chocolate, and pasta. Science. 2018;360(6392):987-992. doi:10.1126/science.aaq021
Stevenson PJ. Industrial Livestock Production. The Twin Myths of Efficiency and Necessity. Compassion in World Farming; 2015:14. Accessed January 15, 2024. https://www.ciwf.org.uk/research/policy-and-economics/industrial-livestock-production-the-twin-myths-of-efficiency-and-necessity/
United Nations. Food and Climate Change: Healthy diets for a healthier planet. United Nations. Accessed January 15, 2024. https://www.un.org/en/climatechange/science/climate-issues/food
Viroli G, Kalmpourtzidou A, Cena H. Exploring Benefits and Barriers of Plant-Based Diets: Health, Environmental Impact, Food Accessibility and Acceptability. Nutrients. 2023;15(22):4723. doi:10.3390/nu15224723
Mathesius U. Are legumes different? Origins and consequences of evolving nitrogen fixing symbioses. Journal of Plant Physiology. 2022;276:153765. doi:10.1016/j.jplph.2022.153765
Semba RD, Ramsing R, Rahman N, Kraemer K, Bloem MW. Legumes as a sustainable source of protein in human diets. Global Food Security. 2021;28:100520. doi:10.1016/j.gfs.2021.100520
hong Y, Tian J, Li X, Liao H. Cooperative interactions between nitrogen fixation and phosphorus nutrition in legumes. New Phytol. 2023;237(3):734-745. doi:10.1111/nph.18593
Marshall S, Petocz P, Duve E, et al. The Effect of Replacing Refined Grains with Whole Grains on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials with GRADE Clinical Recommendation. Journal of the Academy of Nutrition and Dietetics. 2020;120(11):1859-1883.e31. doi:10.1016/j.jand.2020.06.021
Wheat Facts | National Associate of Wheat Growers. Published February 27, 2023. Accessed January 15, 2024. https://wheatworld.org/facts-about-wheat/
Aune D, Giovannucci E, Boffetta P, et al. Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality-a systematic review and dose-response meta-analysis of prospective studies. Int J Epidemiol. 2017;46(3):1029-1056. doi:10.1093/ije/dyw319
WRAP. UK Food Waste & Food Surplus - Key Facts. WRAP; 2023:18. Accessed January 15, 2024. https://wrap.org.uk/resources/guide/waste-prevention-activities/food-love-waste-data
UNEP. Food Waste Index Report 2021. UN Environmental Programme; 2021:100. Accessed August 11, 2023. http://www.unep.org/resources/report/unep-food-waste-index-report-2021

Published: June 2024