Body shape and bust variations by ethnicity and BMI using SizeUSA data

Abstract This study examines variations in body shape and bust-related measurements, focusing on bust, waist, and hip dimensions while also considering the influence of BMI and ethnicity. Employing a quantitative approach, it analyzes anthropometric data of 2,750 women aged 26–45 from the SizeUSA database. The sample includes the following ethnicities: White, Black, Asian, non-Mexican Hispanic, and Mexican Hispanic. Variations in body measurements, BMI, and bra cup sizes across these groups are statistically analyzed using analysis of variance, cluster analysis, and chi-square tests. Body shape analysis reveals three shape clusters; Triangle shape (larger hips compared to upper body with moderate bra cup size), Rectangle shape (smaller waist–hip differences with a moderate cup size), and Inverted Triangle shape (larger upper body compared to hips with a large cup size). Each ethnic group exhibited distinct body shape patterns as follows: The Triangle group comprised a higher percentage of Black and White populations. The Rectangle group comprised a predominantly Asian population, while the Mexican Hispanics and non-Mexican Hispanics dominated the Inverted Triangle group. This study highlights trends in bra cup sizes across weight categories and suggests potential correlations between the former and body shape types. It contributes insights into the relationships among ethnicity, BMI, and bust-related measurements; identifies specific body shape clusters and bra size distributions; and offers valuable information in designing inclusive and well-fitted foundation garments for a diverse population.