The Environmental Benefits of Adopting a Plant-Based Diet

Diet and Food Production Impact Health and the Environment

Our diet and how the foods included in it are produced affect not only our health but also the environment. Approximately one-third of human-induced greenhouse gas emissions are related to the cultivation, processing, transportation, distribution, and preparation of food.

Positive Environmental Effects of a Plant-Based Diet

A new study has shown that adopting a plant-based diet has positive environmental effects, such as reducing carbon emissions by up to 46%. This refers to the carbon footprint associated with our daily activities.

The study simulated four real, isocaloric (2000 kcal/day) weekly menus with different patterns: Mediterranean (omnivorous), pescovegetarian, ovolactovegetarian, and 100% vegetal (treated as a vegan diet in nutrition, though the term carries other philosophical implications).

The researchers evaluated two essential aspects: nutritional adequacy (whether the menu covers necessary nutrients) and environmental footprint (resources consumed from farm to fork and daily waste generated). The latter includes the equivalent CO₂ emissions, land use, water consumption, and effects on ecosystems and human health (ozone and particulate emissions, eutrophication, ecotoxicity).

Nutrition: Just What’s Needed

All four dietary patterns meet macronutrient and protein requirements. The concern with a 100% vegetal diet is that plant proteins lack complete essential amino acid compositions. However, combining legumes (like lentils) and grains (such as rice) typically completes the protein amino acid profile.

Regarding other crucial nutrients, vegetal diets increase fiber intake and reduce saturated fat consumption, resulting in a healthier lipid profile. Nevertheless, some nutrients need attention in the 100% vegetal diet model, such as iodine and vitamin D (covered through iodized salt consumption and sun exposure) and vitamin B12, which should be supplemented.

None of the diet models reached the recommended 250 mg/day of omega-3 (eicosapentaenoic acid and docosahexaenoic acid). However, there are ways to enrich the menu by adding blue fish, consuming fish oil or microalgal oil (for the 100% vegetal option), and

Read more: Omega-3: how much should you take and what are the best food sources?

The calcium in non-dairy diets can match that of a dairy-inclusive diet, thanks to calcium in fortified plant beverages and tofu. In summary, “more plant-based foods, but well-planned”.

Environmental Impact: The Unseen Footprint

The impact on emissions theoretically decreases as the diet becomes more vegetal: up to 46% less CO₂e in the 100% vegetal pattern compared to omnivorous. This decrease not only implies a reduction in global warming but also less ozone precursors, fewer secondary particulates, and improved air quality.

Moreover, the effect extends to land and biodiversity: more vegetal menus reduce land use by 20% to 33%. This is crucial as it relieves pressure on habitats and preserves essential ecosystem services, such as pollination and water regulation, vital for curbing biodiversity loss.

Another evaluated indicator is the water consumption impact in a basin (AWARE), which measures not only liters withdrawn (blue water) but also the relative impact of that extraction according to basin scarcity: how much it reduces availability for others and ecosystems. Here, changes are moderate (a 5% decrease with the 100% vegetal diet) and depend on location and cultivation methods. Not all “water” has the same weight: irrigating 100 liters in an arid area causes more harm than doing so in a humid basin.

Observations also show reductions in acidification and eutrophication—excessive nutrient release—meaning less pressure on soils and waters, as well as lower ecotoxicity. This implies less diffuse contamination, less stress on rivers and seas, and reduced human exposure to harmful substances traveling through the food chain.

However, a note on fish: pescovegetarian menus improve most indicators but may worsen those related to ozone through the cold chain and long transportation. Not all fish have the same footprint; species, origin, fishing methods (more selective than trawling), and logistics (proximity, avoiding air transport, short supply chains) make a difference in this context.

Read more: Fish and shellfish for Christmas? How to choose the healthiest and most sustainable based on its label

Image link

Real Positive Changes with Measurable Effects

What we choose to eat three times a day adds or subtracts from climate change and biodiversity loss. More vegetal menus are an immediate and affordable solution, both at home and in collective eating and public procurement.

Read more: Three crucial changes in the food system to avoid devouring the planet

This transition also helps advance toward achieving UN Sustainable Development Goals (SDGs) in real life: SDG 3 (health), SDG 12 (responsible consumption), and SDG 13 (climate action). Clear rules and aligned markets are needed to accelerate change: carbon footprint labeling, critical nutrient information, low-carbon public procurement, and support for minimally processed, fortified vegetal foods.

Transitioning to pescetarian, ovolactovegetarian, and vegan diets accumulatively reduces the footprint. However, we can start with a well-made Mediterranean diet with high vegetable consumption.

If starting from scratch, expert dietitian-nutritionist support with vegetal diet experience can prevent deficiencies. Then, let’s get practical: less meat (especially ruminant), more legumes, whole grains, fruits, vegetables, and nuts; prioritize origin and season, and choose fortified foods when they add value. With small, consistent, and measurable changes, our plate can reduce emissions, alleviate soil and river pressure, and improve air quality without sacrificing a complete diet.