Nutrition in abrupt sunlight reduction scenarios: a scenario-based modeling study of malnutrition prevention in low-income regions

Abstract

Purpose: An abrupt sunlight reduction scenario (ASRS) can be triggered by a nuclear war, a large volcanic eruption, or an asteroid strike, resulting in global agricultural collapse. A wide portfolio of resilient food interventions has been developed to address these issues, but even if they succeed in providing sufficient food energy for the global population, economic inequality could still result in fatal malnutrition in low-income countries (LICs). Methods: Low-cost diets (<$1/person/day) based on ASRS-resilient foods were optimized to reduce malnutrition with sufficient energy intake. The generated dietary combinations were compared to dietary guidelines. Results: The estimated diets were insufficient to achieve balanced diets, resulting in widespread malnutrition. We find that not only continued international trade but also significant food aid is needed to prevent widespread LIC starvation in a severe ASRS. Severe nutritional deficiencies are present: at the onset (Period 1), vitamins A, E, D, C, B3, B5, calcium, zinc, iodine, and selenium; and in the longer term (Period 2), vitamins E, D, K, B5, B6, B12, zinc, and selenium. Seaweed and single-cell proteins are resilient foods that contain notable quantities of many of these; however, large intakes of these are likely to be unfeasible without extensive processing. Conclusion: To reduce the risk of malnutrition and mass starvation in a severe ASRS, LICs would need to develop the capability to ramp up resilient food production internally, perhaps through international cooperation, and/or establish international trade agreements for food and supplements in case of a disaster. Otherwise, if a global food shock occurs, they risk being left dependent on the mercy of catastrophe-stricken, wealthier nations.

The authors' abstract, as published at the source. American Journal of Clinical Nutrition, 2026 · DOI ↗