Concern about the overconsumption of unhealthy foods is growing worldwide. With high global rates of noncommunicable diseases related to poor nutrition and projections of more rapid increases of rates in low- and middle-income countries, it is vital to identify effective but low-cost interventions. Cost-effectiveness studies show that individually targeted dietary interventions can be effective and cost-effective, but a growing number of modeling studies suggest that population-wide approaches may bring larger and more sustained benefits for population health at a lower cost to society. Mandatory regulation of salt in processed foods, in particular, is highly recommended. Future research should focus on lacunae in the current evidence base: effectiveness of interventions addressing the marketing, availability, and price of healthy and unhealthy foods; modeling health impacts of complex dietary changes and multi-intervention strategies; and modeling health implications in diverse subpopulations to identify interventions that will most efficiently and effectively reduce health inequalities.