Fourth and finally, there was a general lack of focus on the relevant delivery platforms for nutrition interventions. Many studies were not explicit about how and where interventions were delivered, and we had to cross-reference multiple sources to identify the delivery platform for many interventions. Delivery platforms are important and relevant information in terms of replicability, but also for identifying who is effectively reached and missed. Information about delivery platforms is also instrumental in understanding gaps in implementation. A greater emphasis on delivery platforms could enhance the reach of nutrition interventions and could also strengthen the capacity to mobilize resources more effectively. For instance, organizing and grouping interventions by delivery platform (e.g., antenatal care, community centers, schools, clinics) or by the relevant stakeholders required for delivery (e.g., ministries, health care providers, teachers, administrators, transporters, etc.) could have the potential to more efficiently deliver nutrition interventions.
Our findings identified gaps and limitations in the evaluation, scope, targeting, and delivery platforms of nutrition interventions in low- and middle-income countries. First, the monitoring and evaluation of nutrition programs that reported on women's nutrition outcomes was generally inadequate. Many of the studies we identified included small-scale efficacy trials. Although there were many large-scale programs that targeted women and adolescent girls with nutrition-specific and nutrition-sensitive approaches, they lacked rigorous evaluation. Whether the evidence about women's outcomes was limited because they are not systematically measured or because they are not well reported is not clear. Negative results are often not published, and many evaluations of nutrition interventions that are conducted by the same groups responsible for implementing them are typically presented positively. This may have also skewed our findings. More intentional research-quality program evaluation, including of large-scale programs, would provide a stronger evidence base. Of the studies identified in this review, many reported on short-term findings such as changes in knowledge, dietary behaviors, and program coverage. They were limited in their ability to report clinical and anthropometric outcomes for women, the duration of those outcomes, and the feasibility of scaling up programs. There is also a need for systematic, long-term evaluations of interventions whose effects on nutrition outcomes are more distal (e.g., nutrition education compared with micronutrient supplementation). The effects of multisectoral interventions are even more complex to measure. However, frameworks exist to evaluate complex interventions (102) and could be utilized to evaluate the impact of interventions across the life course.