Summary:
Adolescents and young adults generally had the highest dietary greenhouse gas emissions per person between 2000 and 2019, while people aged 60 and over contributed the largest share of the global increase as older populations grew, according to research published in Nature Food.
The analysis covered 141 food products across 22 age groups in 149 countries. Over the study period, global dietary emissions increased by 2.1 gigatonnes of carbon dioxide equivalent, with older adults accounting for 25.4% of that growth. Their rising contribution was driven mainly by population ageing, particularly in high- and upper-middle-income countries, rather than by diets that were more carbon-intensive than those of younger people.
Among adolescents and young adults, higher emissions per person were linked to greater consumption of foods including meat and dairy products. Increased meat intake was the main dietary driver of emissions growth and often coincided with declining nutritional quality. In some low- and middle-income countries, however, higher-emission diets accompanied better nutrition, showing that efforts to reduce food-related emissions must also consider dietary needs, demographic change and national development.
— Press Release —
Teen diets drive highest climate emissions, but older people fuel global surge
Teenagers and young adults tend to have the highest individual environmental impact from their diets, but population ageing is contributing to increases in global dietary greenhouse gas (GHG) emissions – not because older people eat worse diets, but because of increasingly ageing populations.
Publishing their findings in Nature Food, an international research team led by the University of Birmingham, calls on policymakers to consider the urgent implications for food systems and sustainability.
The study highlights that rising emissions are often linked to poorer diet quality, creating a dual crisis of climate pressure and worsening nutrition outcomes. There is also a global inequality dimension, as in Low- and Middle-income Countries (LMIC), higher-emission diets often coincide with improving nutrition.
After analysing diets across 149 countries and 22 age groups – using data from 2000–2019 – researchers found that adolescents (11–19) and young adults (20–29) produce the highest per‑capita food-related GHG emissions worldwide.
Read also: How diet changes could cut food-related climate emissions
The study reveals an important second trend: seniors (60+) are now the fastest-growing contributors to total dietary emissions, particularly in high-income countries, due to population ageing.
Researchers’ key findings included:
- Young people (11–29) have the highest carbon-intensive diets globally, driven by greater consumption of meat, dairy, and processed foods.
- Seniors (60+) are now the fastest-growing source of total emissions, particularly in high-income countries with ageing societies.
- Global dietary emissions rose by 2.1 GtCO₂e between 2000 and 2019, with seniors contributing the largest share of that increase (25.4%).
- Rising meat consumption, especially red meat, is the single biggest driver of dietary emissions growth worldwide – coinciding with worsening nutritional quality.
Corresponding author Professor Yuli Shan, from the University of Birmingham, said: “Our findings challenge the dominant narrative that older populations are the most carbon-intensive consumers and prompts policymakers to face some tough challenges.
“In emerging economies, rising incomes are driving increased consumption of animal products, sharply increasing emissions among younger populations. This creates a growing dilemma for policymakers, namely, how to reduce emissions without undermining nutrition.”
Leading author Yanxian Li, from Chongqing University, said: “We must rethink climate responsibility or face a policy blind spot if interventions focus on only one age group – identifying clear intervention points by age group, whether children and adolescents, young adults, or seniors.”
The study challenges ‘one-size-fits-all’ climate solutions focused on diet alone, calling instead for targeted strategies tailored to age groups and development stages:
- For high-income countries, these blueprints should focus on low-emission, nutritionally adequate diets for ageing populations – addressing rising emissions linked to demographic change.
- For younger populations globally, policymakers should prioritise education and behavioural change – reforming school and youth food environments.
- In LMICs, we must balance nutrition needs with sustainable transitions, whilst investing in local food systems, productivity, and access to diverse diets.
Another corresponding author Professor Klaus Hubacek, from the University of Groningen, said: “In many low- and middle-income countries, increases in emissions have occurred alongside improvements in nutritional quality, meaning that simply reducing certain types of food may have unintended health effects.”
“Food systems already account for around a third of global greenhouse gas emissions. Our research shows that – with the global population both growing and ageing – who we are, as much as what we eat, is becoming a defining factor in future climate trajectories,” said Prajal Pradhan, an associate professor at the University of Groningen and a co-author.
Read also: Ageing population linked to rising household food waste and greenhouse gas emissions
The rise in food-related emissions linked to older people is mostly due to there being more of them, not because their diets are especially harmful. Most of the rise in emissions among older people is simply because people are living longer and having fewer children.
In high‑income regions, older adults now account for the largest share of diet‑related emissions, reaching 22–29% of national totals across countries such as the U.S., Western Europe, and Japan. The increase is driven by population ageing rather than more carbon‑intensive diets.
Teenagers and young adults tend to eat more foods that have a high environmental impact, such as meat, dairy, sugary foods, and drinks. In developing countries, as incomes rise, young people are eating more food overall, which increases emissions further.
Journal Reference:
Li, Y., Yan, J., He, P. et al., ‘Youth lead current dietary emissions while seniors increasingly drive total emission growth’, Nature Food 7, 688–700 (2026). DOI: 10.1038/s43016-026-01383-4
Article Source:
Press Release/Material by Tony Moran | University of Birmingham
Featured image credit: Daniel | Unsplash
