Objective: This study aimed to estimate the trends, projections, and determinants of standalone and Coexisting Forms of Malnutrition (CFM) at global, regional, national, and individual level among children under five in low- and middle-income countries (LMICs). The study also assessed the projection trajectory towards the 2030 GNTs (GNT) for child growth. Methods: Data from 48 LMICs were analysed using the Multiple Indicator Cluster Surveys (MICS) and Demographic & Health Surveys (DHS). Children with complete anthropometry were included for national and individual-level descriptive analyses. Projected prevalence of each form of malnutrition, including CFM, was calculated using the Annual Rate of Change (ARR). Inferential analyses employed generalized linear regression models (GzLM) with two-way interaction terms to identify determinants of each malnutrition type. Findings: By 2030, 22 of 48 LMICs are projected to achieve all three GNT, up from 10 countries currently, while Yemen and Zimbabwe are expected to remain off-track. Stunting is the most prevalent form, affecting 42 countries, with nine nations projected to have over 50% of children affected by any form of malnutrition. Wasting, obesity, and CFM are rising in several countries. Maternal education and household wealth were the strongest determinants, with children of uneducated mothers and from poorest households at highest risk. Inequalities are narrowing slowly, by 1–2% per year, and marked regional disparities persist. Conclusion: Many LMICs are off track to meet child growth targets when CFM in considered alongside standalone indicators. The government and global health partners must strengthen nutrition surveillance systems and equity-focused policies and programs to routinely capture CFM and prevent as well as manage all forms of malnutrition at national and individual levels.