Your dinner choices may have a bigger impact than you think, not only on your personal health, but on the health of the planet, and in turn, everyone who lives on it.
A new study from the Barcelona Institute for Global Health (ISGlobal), published in Environmental Research, has, for the first time in Spain, calculated the human health toll of the environmental impacts tied to the country’s food demand. The results? Meat, fish, seafood and dairy account for more than half of the environmental damage that translates into human disease and disability.
Researchers used a tool called Life Cycle Assessment (LCA) to track the environmental impact of each step in the food system, from production to your plate, and link those effects to public health. They drew on official 2022 consumption data from Spain’s Ministry of Agriculture, Fisheries and Food, then modeled how environmental issues such as climate change, air pollution and toxic exposure contribute to diseases like heart disease, cancer, respiratory illness and malnutrition.
The numbers were striking: in 2022, the environmental impact of Spain’s food demand was linked to the loss of about 447,000 disability-adjusted life years (DALYs), a measure combining years lost to early death and years lived with illness. Ninety-five percent of that impact came from food consumption, with the remaining 5% from food waste.
Of the 16 food groups analyzed, animal-based foods had the greatest impact, with meat, fish and dairy contributing 55% of the total. Climate change was the single largest driver, responsible for 77% of the health burden, followed by air pollution and human toxicity.
The team also tested what could happen if diets shifted. Replacing all meat and dairy with plant-based foods could cut environmental health damage by up to 30%. Eliminating consumer food waste could add another 5% reduction, for a total of 35%. And those changes wouldn’t just help the planet; they would also bring the average diet closer to World Health Organization nutrition recommendations, with more fiber and iron and slightly less protein, calcium and vitamin B12 (still within healthy ranges).
“The proposed changes would not only reduce environmental impact but also bring the average diet in Spain closer to WHO nutritional recommendations, thus moving toward a more comprehensively healthy diet,” said study author Ujué Fresán of ISGlobal.
The findings suggest that small shifts in how we eat, and how much we waste, could pay off twice: by protecting the environment and reducing the long-term burden of diet-related disease.
The authors report no specific funding for this study, though some researchers receive institutional support from Spanish and Catalan research programs and foundations.