Background: Malnutrition is a major global health issue. Orphaned and vulnerable children, such as those in institution-based care (IBC), are especially at-risk. Some 9.42 million children live in IBC worldwide but data on this group is sparse. The overall aim of this PhD was to generate evidence to improve future nutritional and feeding services for children living within IBC globally. Methods: A systematic review compiled and evaluated available evidence on the nutritional status of children in IBC. Two retrospective analyses of surveillance data described the current nutritional and feeding status of children living within IBC who participate in the Child Nutrition Program (CNP). Shewhart control charts and funnel plots explored inter-site and over-time variations in nutritional status and logistic regression examined associations between feeding difficulties and disability taking into account natural variation. An evaluation of the process described the implementation of CNP. Results: Children in IBC were commonly born prematurely 294/697 (42.2%) or low birth weight 514/895 (57.4%). Many had disabilities 739/2926 (25.3%), were malnourished 1048/2812 (37.3%) and/or anemic 717/2494 (28.7%). Children with disabilities had higher prevalence of malnutrition and feeding difficulties compared to counterparts without disabilities. The adjusted risk of having a feeding difficulty was 5.08 times (95%CI: 2.65–9.7, p ≤ 0.001) higher in children with disabilities than those without. Many children saw their feeding difficulties resolve after 1-year in CNP. Suboptimal hygiene, dietary and feeding practices were reported in IBC. Mixed-methods evaluation of the implementation of CNP indicates that strong leadership/relationships, frequent training, funding and adequate staffing are needed for successful implementation. Conclusion: Malnutrition (stunting, underweight and wasting) and feeding difficulties are common in IBC, especially among children with disabilities. Supporting safe interactive and nutritious mealtimes should be prioritized to ensure overall health and development. Program evaluations can help improve interventions and underpin programmatic growth and scaling.