For those working in the field of nutrition, it can seem like everything is part of the food system, from agriculture to marketing, because so many factors influence how we produce, distribute, and cook food. That broad scope is one reason why the visualization offered by 3ie's new Evidence Gap Map on food systems interventions has the potential to be so useful. It's also why it is the largest gap map 3ie has ever produced.

Expert policymakers and researchers joined 3ie for a panel discussion Friday on the new gap map, highlighting the ways it can be useful and the findings that surprised them.

"It will really help us in utilizing evidence from food systems interventions to improve nutrition," said Christoph Langenkamp, Programme Director, Knowledge for Nutrition (K4N). "The map will provide a visual and interactive display of this evidence in different sectors and subsectors."

Technical approaches like nutrient fortification appear to have been evaluated more often than grassroots type approaches, said Martin Hoppe, BMZ's Head of division for food and nutrition security, global food policy, and fisheries. This finding may suggest an inordinate focus on topics that are "sexy" or "the current trend."

"There is a lot of research, but it's not distributed evenly," he said. "There are clearly fields where the (research) coverage on interventions is much more dense than on others."

The map also suggests that researchers do not always study the most appropriate outcome for a given intervention. For example, many food fortification studies were evaluated using anthropometric outcome measures like height or weight, rather than more direct measures of nutrient intake, said Marie Ruel, Director of Poverty, Health, and Nutrition Division, International Food Policy Research Institute (IFPR).

"This [anthropometric measurement] is not the best outcome for a fortification study," Ruel said. "Lots of other things need to fall into place [to see an effect] … it's very possible that a lot of studies [report] negative impacts or don't show impacts because they didn't choose the right outcomes."

To compound that issue, many studies also do not include any intermediate outcome measures to help show why an intervention did – or did not – work as expected.

"We are not actually learning about how to achieve these outcomes because we are not measuring the causal pathway," said 3ie Evaluation Specialist Charlotte Lane.

Several panelists noted their surprise at the relative absence of evaluations linking food systems interventions and gender outcomes.

"That was one of the most striking surprises, why is there so little evidence [on women in the food system]?" Langenkamp said.

Most of the studies that did measure gender outcomes used the same measurement approach, providing a narrow picture, said Thalia Sparling, postdoctoral fellow, Innovative Metrics and Methods for Agriculture and Nutrition Actions (IMMANA).
"There are a lot of missing other aspects of equity," Sparling said.

Also, panelists agreed that the map is most useful when used as a tool to direct further inquiry, and that it cannot provide all the answers on its own. The map should not be viewed as a magic genie with the answers, but rather as a roadmap to provide directions, Sparling said.

"It allows you to step back and see the broader picture, but these maps are never going to be specific enough that they tell you everything you need to know," Sparling said.

The interactive online map can be viewed here, where users can apply filters to search for the topics that interest them. The full report on the map and a brief summary of its findings are here.