Evolution of child acute malnutrition during war in the Gaza Strip, 2023-2024: retrospective estimates and scenario-based projections.

Nutritional status has been compromised by ongoing war and restrictions on food deliveries in the Gaza Strip. We developed a mathematical model that outputs retrospective estimates and scenario-based projections of acute malnutrition prevalence among children given caloric intake and other factors. We present here the model and its application to the crisis in Gaza. We extended an existing mechanistic model for weight change as a function of energy balance, calibrating it to represent variability in growth curves observed in pre-war Gaza. We simulated open cohorts of children exposed to time-varying caloric intake, infant exclusive breast-feeding prevalence, incidence of infectious disease and coverage of malnutrition treatment, while allowing for adult caloric sacrifice to supplement child intake in times of food scarcity. The model accurately replicates growth standards, pre-war growth patterns and expected parameter dependencies. It suggests that a considerable increase in acute malnutrition occurred in northern Gaza during early 2024. Projections for late 2024 include a serious nutritional emergency if relatively pessimistic assumptions are made about food availability. The model may hold considerable promise for informing decisions in humanitarian response but requires further validation and development.