The body mass index (BMI) reflects current net nutrition and health during economic development. This study introduces a difference-in-decompositions approach to show that although 19th century African-American current net nutrition was comparable to working class whites, it was made worse-off with the transition to free-labor. BMI reflects net nutrition over the life-course, and like stature, slave children’s BMIs increased more than whites as they approached entry into the adult slave labor force. Agricultural worker’s net nutrition was better than workers in other occupations but was worse-off under free-labor and industrialization. Within-group BMI variation was greater than across-group variation, and white within-group variation associated with socioeconomic status was greater than African-Americans.
BMI variation current net nutrition Oaxaca decomposition