September 17, 2021 | Foods | Source |
Introduction: Researchers from the University of Porto and Universidade Aberta (Portugal), in collaboration with EMBRAPA (Brazil), conducted a Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA)-guided literature review to examine how consumption of local seasonal foods influences sustainable food consumption. The review examined how “seasonal” and “local” foods are defined, which sustainability dimensions are addressed, and what evidence links local seasonality to environmental, economic, and social outcomes, with concepts mapped and synthesized across the three pillars.
Key findings: The review found wide inconsistencies in how “seasonal” and “local” are defined. Seasonality is interpreted as: “in season” (based only on availability), “produced in season” (grown naturally without high-energy inputs), and “local seasonal” (grown and consumed nearby in its natural season without energy-intensive storage). “Local” is described in three ways: geographic (distance or political boundaries), holistic (short supply chains and trust networks), and regional (identity or specialty foods). Among the 116 studies reviewed, only 34 directly examined seasonality, and just 6 considered all three pillars of sustainability. Most focused on economic aspects (willingness-to-pay analyses), with far less attention given to environmental or social dimensions.
The review found that off-season greenhouse production can emit more than long-distance imports, challenging the “food miles” narrative and the “local trap.” The UK’s Department for Environment, Food and Rural Affairs (DEFRA) promotes local seasonality—foods grown outdoors in their natural season and consumed nearby—which offers stronger sustainability benefits than global seasonality. The authors call for clearer labeling rules, supported by life-cycle assessment (LCA) and broader sustainability metrics, while policies should back diversified farming and short supply chains to maximize environmental, economic, and social gains. Key gaps remain in integrating all three pillars, involving multiple stakeholders, and expanding research in developing countries.
