Closing the Loop:
Evaluating Food Waste-to-Feed Pathways for a Circular Food System
This report reviews eight waste-to-feed technologies and dives deep into four innovative and underutilised approaches: swill, single-cell proteins, insect farming, and biochar feed additives. By examining production processes, commercial viability (including regulatory statuses and business economics), environmental footprints, and case studies, we identify which pathways are gaining real commercial traction and which present the greatest opportunities for positive impact.
About the Report
Every year, roughly one-third of all food produced is lost or wasted, resulting in significant climate and economic impacts. The priority remains preventing waste and rescuing surplus food for people. But even with strong systems, some waste is inevitable. That is why recycling solutions are essential, alongwith using safe food side streams in animal nutrition, which already accounts for a share of surplus food recovery in the US.
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Waste-to-feed pathways can divert material from landfill, reduce disposal costs, and, under the right conditions, help displace demand for resource-intensive feed inputs. Some routes, such as brewers’ spent grain and former-food meals, are established and scaled, but are constrained by feedstock limits and market saturation. Meanwhile, newer approaches aim to broaden the range of usable inputs and unlock additional circular value.
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This report reviews eight waste-to-feed technologies and provides a deeper analysis of four innovative and underutilised pathways: swill, single-cell proteins, insect farming, and biochar feed additives. The report assesses production processes, commercial viability (including regulatory and economic factors), environmental footprints, and case studies. To support clear comparison across options, it applies Technological Readiness Levels (TRLs) to map maturity and bankability, offering funders and food businesses a practical view of where the most genuinely circular opportunities are emerging.
Recommendations
To advance the most promising new waste-to-feed pathways from alternatives to established pillars of a more circular food system:
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Businesses: Adoption decisions will depend on proximity to feedstocks, logistics feasibility, and regulatory frameworks. Prioritise prevention first, then food rescue, with waste-to-feed used only for unavoidable residues.
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Funders: The choice is between backing established models with incremental gains or engaging with newer approaches that carry higher risk but the potential for long-term impact. Not all waste-to-feed pathways deliver equal climate or economic benefits.
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Single-cell proteins: SCPs have a clear trajectory to scale, particularly in aquafeed and pet food, provided that energy integration, feedstock access, and regulatory approvals are secured.
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Insect farming: Continues to face challenges including energy costs, regulatory restrictions, weak environmental performance, and an inability to utilise food waste beyond items already authorised in conventional livestock feeds, potentially limiting its near-term role.
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Swill and biochar feed additives: Swill is proven in Asia, where it is supported by policy and infrastructure but remains restricted in Europe and the U.S. Biochar feed additives occupy an emerging niche, offering both potential animal productivity benefits and carbon sequestration.
