Pre-registration of the analytical protocol for the Gender-Social Health Burden Index (GSBI) project — Advancing Women's Nutritional Health Equity in Nigeria. This protocol documents all pre-specified research questions, outcome variables, exposure variables, causal contrasts, and the five-stage analytical pipeline (survey-weighted regression, PCA, K-medoids clustering, TMLE, and Double/Debiased Machine Learning) prior to receipt and analysis of NDHS 2018 outcome data. Funded by the Global Development Network (GDN) Japanese Award for Outstanding Research on Development — 2nd Prize (USD 20,000). Principal Investigator: Anthonio Oladimeji Gabriel, University of Ibadan, Nigeria.