Abstract
In peri-urban Southern Africa, low-income households simultaneously experience high levels of micronutrient deficiencies and paradoxical food loss driven by inadequate storage infrastructure and limited food preservation capacities. This quasi-experimental study evaluated the effectiveness of a six-month participatory food system intervention on household food waste reduction and dietary diversity among 320 low-income households in peri-urban Gauteng, South Africa. Households were allocated to an intervention cohort (n = 160) participating in community-led nutrition education, low-cost solar preservation workshops, and localized surplus food redistributions, or a control cohort (n = 160) receiving standard municipal food relief. Dietary diversity was assessed using the 12-item Household Dietary Diversity Score (HDDS), while household food waste was tracked using mixed-method waste diaries validated by weekly physical audit spot-checks. At baseline, dietary diversity was constrained across both groups (mean HDDS: 4.12 vs. 4.08), with edible food waste averaging 88.4 g/capita/day. At endline, difference-in-differences regression models revealed a significant increase of 1.74 food groups in the intervention arm relative to controls (p < 0.001), characterized by increased consumption of indigenous leafy vegetables and legumes. Concurrently, avoidable household food waste in the intervention group decreased by 42.6% to 50.7 g/capita/day (p < 0.001), with the largest reductions observed in perishable produce. These findings demonstrate that participatory, community-embedded interventions linking waste minimization to household culinary practices can cost-effectively enhance nutritional resilience and food security in resource-constrained peri-urban contexts.