Food Systems and Nutrition Evidence Gap Map

Ending hunger is one of the Sustainable Development Goals. To do this, many development organizations are working within the food system. This has resulted in an explosion of research regarding what interventions work within the food system to improve food security and nutrition outcomes. However, this literature is massively disorganised and difficult to make sense of. This EGM systematically collates all impact evaluations and systematic reviews of impact evaluations relating food systems interventions to food security and nutrition outcomes. 


To address the challenge of malnutrition and food insecurity, the International Initiative for Impact Evaluation (3ie), with support from Innovative Methods and Metrics for Agriculture and Nutrition Actions, was commissioned by Deutsche Gesellschaft für Internationale Zusammenarbeit to develop an evidence gap map (EGM) providing an overview of the literature relating food systems interventions to food security and nutrition outcomes in L&MICs.

A total of 2,035 studies were identified for inclusion: 178 systematic reviews and 1,838 impact evaluations. There has been a rapid increase in the number of studies published since 2000, with the largest increase in interventions aiming to improve the food supply chain or consumer behaviour within food systems. Impact evaluations were primarily located in Sub-Saharan Africa (33%), South Asia (20%), and East Asia and the Pacific (17%). Over half were conducted in rural areas. 

Several interventions, including some that have been widely implemented, have weak evidence bases. We did not identify any impact evaluations related to advertising regulations, food waste education programs or packaging of food. There was very little evidence related to governmental price manipulations and post-harvest processing interventions, despite these being widely implemented. Conversely, other interventions, like fortification, supplementation, the direct provision of food, and nutrition classes, have been massively over studied relative to the rest. 

There is a focus on easily randomized interventions, such as fortification and supplementation, rather than more difficult to quantify interventions. Many of the less studied interventions, such as advertising regulations and price manipulations, are implemented at the national scale. As the reach and resources of an intervention increases, so does the ethical imperative to evaluate it. Researchers should adopt quasi-experimental designs to evaluate these more challenging.

The effects of food systems interventions on food security and nutrition outcomes in LMICs

The devastating impacts of malnutrition and food insecurity are well documented. In low- and middle-income countries (L&MICs), constraints and complexities within food systems are significant drivers of these conditions. As a result, there has been a significant global focus on improving food systems to facilitate better food security and nutrition outcomes. The evidence base regarding the impact of interventions within food systems in achieving these aims is massive, but complicated and disorganized, making it difficult for donors, policymakers and practitioners to navigate. 3ie's Evidence Gap Map addresses this challenge.