Sustainable development is the need of present and future generations to ensure human growth and balance in earth biodiversity. Nutrition, a development indicator, is linked to all sustainable development goals set by the United Nations, and thus it remains the most important factor of all time. On the other hand, a lack of sufficient nutrition in children, can lead to developmental difficulties, illness, and mortality, as well as a threat to human multidimensional growth. Undernutrition, a condition characterised by a lack of proper nutrition, manifests as stunting, wasting, and being underweight and has long-term consequences such as impaired health, lower school and educational performance, reduced cognitive ability and development, poor socioeconomic skills, lower economic productivity, and loss of human capital and household income. The presence of more than one type of undernutrition among children increases the risk of death in children by a 4–12-fold. As a result, reducing levels of undernutrition is crucial to reaching the SDG of reducing child mortality. Using a Bayesian geo-additive regression approach, this study examines the risk variables, including spatial variability, related to the co-existence of stunting, wasting, and underweight among Indian children. Data from the National Family and Health Survey (NFHS)-V, available from www.dhsprogram.com, were used for this purpose. The goal of using a Bayesian geo-additive regression method is to model the linear, nonlinear, and spatial impacts of various risk factors on a unified platform, thereby exploring the possible uneven effects of some risk factors and spatial variability of the study variable caused by unobserved socio-environmental and cultural factors. The findings of this study should give insight on the significant factors and impact-behavior of metric covariates on the coexistence of undernutrition. Furthermore, results on spatial effects on the study variable would aid in identifying geographical areas in India that lagged behind in SDGs developmental indicators related to child nutrition.