A new study of 30-year changes in the Brazilian diet finds that increased consumption of ultra-processed foods is linked to worsened impacts on the environment, and echoes dietary changes in the UK.
A new study finds that over the last 30 years, Brazil has undergone a nutrition transition toward a diet higher in ultra-processed foods, and that of food types consumed, these have been the largest contributor to worsening impacts on greenhouse gas emissions, the nation’s water footprint and ecological footprint, such as deforestation.
Ultra-processed foods include reconstituted meat products, such as sausages; ready meals; margarines; sweets; soft drinks; and other foods which contain artificial additives like sweeteners and flavours.
Whilst the negative effects of high consumption of ultra-processed foods on health have been outlined for over a decade - including links with obesity, coronary heart disease, diabetes and cancer - there had previously been very little understanding of its effects on the planet.
Experts argue that Britain went through a similar nutrition transition over the last 100 years, and warn that as the economies of more countries grow, so will the trend in the consumption of ultra-processed foods, which could adversely affect their ability to meet climate change targets.
Published in the journal The Lancet Planetary Health, the study is the first of its kind to use nationally representative data over such a long time-frame to demonstrate how changes in a nation’s diet can affect its contribution to climate change.
The international collaboration of authors, including from the University of São Paulo, Brazil; City, University of London; the University of Manchester; Brunel University London; and the University of Sheffield used household budget survey data taken from urban Brazilian households between 1987 to 2018.
They calculated the environmental impact of food items purchased, per 1,000 calories (kcal) consumed, for four food groups outlined by the widely used NOVA system: unprocessed/minimally processed foods (G1); processed culinary ingredients (G2); processed foods (G3); and ultra-processed foods (G4).
The study found that while the proportion of G1 and G2 foods in the households’ diet had decreased, the amount of G3 and G4 foods consumed had increased. It found that the increasing environmental impact of G4 foods was driven by an increase in consumption of ultra-processed meat, which at least doubled its contribution to daily environmental impacts per individual, reaching about 20 per cent of total diet-related footprints over the 30-year time-frame.
Per 1,000 calories consumed, these changes in the diet were associated with a 21 per cent increased contribution to greenhouse gas emissions, 22 per cent increased contribution to the nation’s water footprint and 17 per cent increased contribution to its ecological footprint.
Nutritionist, and first author of the study, Jacqueline Tereza da Silva, of the Department of Preventative Medicine, University of São Paulo, said:
Dr Christian Reynolds
Co-author of the study, Dr Christian Reynolds, Senior Lecturer at the Centre for Food Policy, City, University of London said:
Dr Ximena Schmidt, co-author and Global Challenges Research Fellow at the Centre for Sustainable Energy Use, Brunel University London:
The study is published in the journal, The Lancet Planetary Health.
The project was funded by the Science and Technology Facilities Council Global Challenges Research Fund (STFC GCRF).