How and why are Theory of Change and Realist Evaluation used in food security contexts? A scoping review

The complex ways in which food security actions lead to nutrition and other health outcomes make it important to clarify what programs work and how, with theory-driven evaluation emerging as a promising approach to evaluate complex programs. However, it is unclear how and why theory-driven evaluation is applied in food security contexts. Our objective is to examine the development and use of Theory of Change and Realist Evaluation to support food security programs globally. Using a systematic search and screening process, we included studies that described a food security program, used a Theory of Change or Realist Evaluation, and presented original research or evaluations. We found a total of 59 relevant Theory of Change studies and eight Realist Evaluation studies. Based on our analysis, Theories of Change arose in response to three main problems: 1) the need to evaluate under complexity; 2) challenges with evaluation; and, 3) information gaps surrounding a program. In contrast, Realist Evaluation was reported to be developed primarily to understand a program's outcomes. Reflecting on the problem to be addressed in the evaluation would help improve understandings of the evaluation context, which would then inform the choice and design of an evaluation approach.