Dietary environmental impacts and quality differ by socio-demographic characteristics

Area of Science:

• Environmental Science
• Nutritional Science
• Food Systems Analysis

Background:

• Global food systems face pressure to become more sustainable.
• Current environmental footprint models often lack individual and contextual dietary variation.
• Understanding diet-environment links is crucial for effective policy.

Purpose of the Study:

• To develop a harmonized model estimating diet-related environmental impacts (climate, water, land) and dietary quality (AHEI).
• To analyze these impacts across diverse socio-demographic subgroups globally.
• To identify patterns for targeted sustainable dietary transition strategies.

Main Methods:

• Integrated a global model with individual food intake and supply chain data.
• Estimated climate (kgCO2e/d), water, and land footprints per capita.
• Assessed dietary quality using the Alternative Healthy Eating Index (AHEI) across 72 subgroups in 165 countries.

Main Results:

• Significant disparities in environmental footprints exist across socio-demographic groups.
• Highly educated urban men (15-34 yrs) had the highest emissions (5.66 kgCO2e/d); low education rural women (35-54 yrs) had the lowest (2.85 kgCO2e/d).
• Improved AHEI scores correlated with reduced environmental impacts: 5% AHEI increase linked to 7.7% lower GHG emissions, 4.4% water, and 7.2% land footprint reduction.

Conclusions:

• Dietary quality is strongly linked to environmental sustainability.
• Heterogeneity in diet quality and environmental impacts necessitates tailored, not one-size-fits-all, interventions.
• Targeted strategies are essential for accelerating sustainable food system transitions globally.