This report presents a quantitative analysis of data from the National Infant Development Survey, focusing on a cohort of individuals tracked since 1958. The analysis employs SPSS to examine relationships between variables such as Body Mass Index (BMI) at ages 7 and 50, respondent's sex, father's education, and O-level qualifications. The study tests two main hypotheses: the correlation between BMI at different ages and the association of adiposity at age 50 with education and sex. Preliminary statistical analysis includes descriptive statistics and frequency distributions. Correlation analysis reveals a moderate relationship between BMI at ages 7 and 50. Regression analysis is conducted to assess the influence of sex on BMI, with interpretations of the statistical significance. The report concludes that there is no significant relationship between body mass index and sex. The report includes statistical tables, correlation matrices, and regression outputs to support the findings.