Plant-based diets – an underutilised way to tackle our health and climate crises

Could cutting our meat and dairy consumption be key to improving our health as well as instrumental in dealing with climate change?

Originally posted on on 6 March 2024

In this article, Dr Shireen Kassam, Consultant Haematologist and founder of Plant-Based Health Professionals UK, discusses how healthcare systems can influence the adoption of plant-based diets for the benefit of patients and the planet.

As healthcare professionals we are naturally interested in and supportive of actions that improve health in its broadest sense. Yet when it comes to discussing diet choices and the food environment, there seems a reluctance to embrace change. For doctors at least, a lack of nutrition education supports the status quo, along with concerns around restricting choice or upsetting patients. However, health promotion and counselling should be a part of all health professionals’ skill set. The impact of diet change can be truly remarkable. Embracing change starts with ourselves so that we can role-model with confidence and advise with credibility.

Improving human and planetary health

Unhealthy diets are a key driver of the chronic ill-health epidemic, with dietary risk factors now being the leading cause of chronic conditions and premature death.1 At the same time, our food system is at the centre of the climate and ecological crises.2,3

Our diets are too high in meat and ultra-processed foods and insufficient in the plant foods that promote health. This is leading to more than 12 million premature deaths globally every year from conditions such as cardiovascular disease, type 2 diabetes and cancer.4 Moreover, if we all ate a diet typical of high-income countries, we would require the resources of 7 planet Earths to feed the world.5 Shifting to a plant-based diet is one of the single most impactful actions we can take to improve our own health and that of the planet.3

Making proportionate changes

The best available evidence informs us that, without transitioning our food system away from animal agriculture, we cannot meet our climate and nature commitments and will not be able to limit global warming to below 1.5 °C or even 2 °C.6 Agriculture contributes at least a third of all greenhouse gas emissions and is the primary cause of biodiversity loss, threatening up to 90% of species with extinction.

The largest contribution comes from farming animals. Yet we can still feed a projected global population of 10 billion while keeping the food system within planetary boundaries if we all shift to a healthy plant-based diet. The EAT-Lancet Commission diet, also known as the planetary health diet, derives more than 85% of energy from fruit, vegetables, whole grains, beans, nuts and seeds.2 The diet does not have to be 100% plant-based, but it can be, to gain the maximum benefit for the planet.7 If choosing to consume animal-sourced foods, these should be limited to 1 portion of red meat, 2 portions of poultry and 3 eggs per week. Dairy consumption is not considered essential. High-income countries like the UK need to make the greatest change with an 80% reduction in animal foods, while increasing the consumption of whole plant foods.

Moving away from meat and dairy consumption

The greatest impact comes from removing red meat and dairy from the diet, the production of which contributes to 57% of agricultural emissions globally while being responsible for 16% of all diet-related deaths (1.9 million). In the UK, the agriculture sector contributes almost 45% of the UK’s greenhouse gas emissions, with red meat and dairy accounting for 74% of these emissions. In addition, around 42,000 deaths annually are associated with excessive consumption of dairy, red meat and processed meat and 70,000 deaths are associated with insufficient intake of nutritious plant-based foods (such as fruits, vegetables, legumes, whole grains, nuts and seeds).4

Even small dietary changes have a big environmental impact. Replacing 30% of meat with plant protein could offset almost all global aviation emissions, free up an India-sized carbon sink that could absorb CO2 from the atmosphere and save 7.5 million swimming pools’ worth of water a year.8 If we were bold and supported a fully plant-based transition, we could return 75% of farmland back to nature, allowing a drawdown of carbon equivalent to 16 years’ worth of emissions from fossil fuel use.9

Health benefits of a plant-based diet

Of particular importance to healthcare, a plant-based diet is associated with considerable health benefits, with significant reductions in cardiovascular disease, type 2 diabetes, obesity, certain cancers and dementia.2,10,11 Further co-benefits include reductions in the use of antibiotics in farming and consequently the risk of antimicrobial-resistant infections.12,13 Similarly, 3 of 4 new and emerging infections with pandemic potential come from animals; the next pandemic is predicted to arise from industrialised animal farming, likely a bird flu.14

How can healthcare influence dietary change?

Healthcare systems around the world have the potential to influence more widespread dietary change. For example, the NHS has almost 1.3 million employees and serves around 140 million meals to hospital patients each year. Switching to a plant-based menu could reduce food-related carbon footprint by more than 50%.15 £633 million is spent on inpatient food provision, yet studies have shown that a plant-based diet would actually cost a third less in the UK.16 In addition, economic modelling suggests billions in health-related cost savings for the NHS.17

Government subsidies away from meat and dairy towards healthy plant-based foods would help to reduce the cost further. A real-world example showcasing what can be achieved comes from New York City. Here, the Mayor, Eric Adams, has championed plant-based meals as the default in 11 city hospitals.18 This has led to 60% of meals consumed being plant-based, with reductions in food cost, excellent patient satisfaction and a 36% reduction in food-related greenhouse gas emissions. The beauty of a plant-based diet is that is adaptable to all traditional and cultural diet patterns, making it inclusive, delicious and nutritious.

Barriers to adopting a plant-based lifestyle

Policy documents and sustainable healthcare curricula all state the broad benefits of a plant-based diet. Yet action is too slow, given that we have already breached 6 of the 9 planetary boundaries and now have less than a decade to make meaningful changes to ensure a future liveable planet.

Sadly, industry influence from a powerful meat and dairy lobby is hampering meaningful change. Many healthcare professionals still follow the narrative that meat and dairy are essential; the co-opting of doctors and scientists for industry benefit reminds us of a time when doctors were advertising cigarette smoking. This is not helped by the fact that farming policy and subsidies, certainly in the UK, do not align with health or climate goals. More than 80% of farmland is used to raise animals for food, leading to an excess of meat production, while the UK is reliant on imports for foods that promote health, such as fruit and vegetables.


I am hopeful that the tide is changing. Some doctors are now referring to the need for plant-based dietary change as ‘a moral imperative’19,20 and plant-based options are more widely available. Health professionals need to show leadership, and this should start with getting our own house in order. Actions such as removing red and processed meat from healthcare menus, offering plant-based meals and dairy alternatives as the default and adding our voice to lobbying efforts, such as endorsing the Plant Based Treaty, would go a long way. The beauty of diet change is that we don’t need to wait. We can all commit to adopting a plant-based diet today.


  1. GBD 2017 Diet Collaborators. Health effects of dietary risks in 195 countries, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet 2019;doi:10.1016/S0140-6736(19)30041-8.
  2. Willett W, Rockström J, Loken B, Springmann M, Lang T, Vermeulen S et al. Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems. Lancet 2019;6736:3–49.
  3. Poore J, Nemecek T. Reducing food’s environmental impacts through producers and consumers. Science 2018;6392:987–992.
  4. Romanello M, Di Napoli C, Green C, Kennard H, Lampard P, Scamman D, et al. The 2023 report of the Lancet Countdown on health and climate change: the imperative for a health-centred response in a world facing irreversible harms. Lancet 2023;402:2346–94. Available at:
  5. Eat Forum. Diets for a Better Future. Published 2020. Available at:
  6. Clark MA, Domingo NGG, Colgan K, Thakrar SK, Tilman D, Lynch J et al. Global food system emissions could preclude achieving the 1.5° and 2°C climate change targets. Science 2020;370.
  7. Takacs B, Stegemann JA, Kalea AZ, Borrion A. Comparison of environmental impacts of individual meals – Does it really make a difference to choose plant-based meals instead of meat-based ones? J Clean Prod 2022;379:134782. Available at:
  8. Madre Brava. Replacing 30% of meat with plants proteins could offset almost all global aviation emissions, free up an India-sized carbon sink and save 7.5 million swimming pools worth of water a year. Published 2 November 2023. Available at:
  9. Hayek MN, Harwatt H, Ripple WJ, Mueller ND. The carbon opportunity cost of animal-sourced food production on land. Nat Sustain 2021;4:21–24.
  10. Springmann M, Wiebe K, Mason-D’Croz D, Sulser TB, Rayner M, Scarborough P. Health and nutritional aspects of sustainable diet strategies and their association with environmental impacts: a global modelling analysis with country-level detail. Lancet Planet Heal 2018;2:e451–e461.
  11. Laine JE, Huybrechts I, Gunter MJ, Ferrari P, Weiderpass E, Tsilidis K et al. Co-benefits from sustainable dietary shifts for population and environmental health: an assessment from a large European cohort study. Lancet Planet Heal 2021;doi:10.1016/S2542-5196(21)00250-3.
  12. Van Boeckel TP, Glennon EE, Chen D, Gilbert M, Robinson TP, Grenfell BT et al. Reducing antimicrobial use in food animals. Science 2017;357:1350–1352.
  13. Murray CJ, Ikuta KS, Sharara F, Swetschinski L, Robles Aguilar G, Gray A et al. Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis. Lancet 2022;399,629–655.
  14. Hayek MN. The infectious disease trap of animal agriculture. Sci Adv. 2022;doi: 10.1126/sciadv.add6681.
  15. 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;2:198–209.
  16. Springmann M, Clark MA, Rayner M, Scarborough P, Webb P. The global and regional costs of healthy and sustainable dietary patterns: a modelling study. Lancet Planet Heal 2021;doi:10.1016/S2542-5196(21)00251-5.
  17. Office of Health Economics. Could plant-based diets transform health care spending? Available at:
  18. NYV Health and Hospitals. Mayor Adams & NYC Health + Hospitals Announce Successful Rollout and Expansion of Plant-Based Meals as Primary Option for Patients in NYC Public Hospitals. Published 29 September 2022. Available at:
  19. Hull SC, Charles J, Caplan AL. Are We What We Eat? The Moral Imperative of the Medical Profession to Promote Plant-Based Nutrition. American Journal of Cardiology 2023;188:15–21.
  20. Kassam S, Freeman L. It’s time for healthcare professionals to demand a plant-based food system. British Journal of General Practice 2021;71:554.