A rapid realist review of household gardening interventions for improving vegetable consumption in low- and middle-income countries (LMICs)

Abstract Background Household gardening is a widely promoted strategy to address low levels of vegetable consumption and improve overall diets in low- and middle-income countries (LMICs). However, existing studies reveal variable effectiveness across different contexts and program designs. This study uses a realist lens to, first, identify three common impact pathways of household gardening interventions from existing literature—production, income and knowledge pathways—and, second, elucidate causal configurations where specific mechanisms are triggered that motivate or demotivate households to follow these pathways of improving vegetable consumption through household gardening. Third, we discuss these findings to provide entrance points to make these interventions more effective in improving vegetable consumption and overall diets. Results This study applies a Rapid Realist Review of published literature on household gardening in LMICs. A total of 24 studies were found that could be used in developing initial programme theories on household gardening. Using a realist approach to evidence synthesis, a total of 11 programme theories, written as intervention-context-mechanism-outcome (ICMO) configurations, were identified and mapped along the three impact pathways. An expert panel was convened, and key informant interviews undertaken to identify the most impactful and actionable configurations. Various mechanisms underlie the motivation of households to start and maintain household gardening, contingent on specific contextual conditions, such as the opportunity to be food secure and resolve household expenses, individual curiosity and experimental nature, social connectedness, self-efficacy, sense of responsibility, and opportunities for resource sharing and knowledge exchange. Conclusions This study contributes a deeper assessment of household garden interventions than has previously been available. The various identified ICMOs linked to the three impact pathways can be used in the design of programs to make them more cognizant of social and personal context, and effective in improving vegetable consumption in LMICs. Household gardening programs can consider leveraging multiple intervention components at the individual level, while consciously accounting for constraining personal, household, social and environmental contexts that impact motivation and ability to practice gardening. Continuing research is needed to advance agricultural interventions such as household gardening to improve diets and nutrition in LMICs.