The average height of a black woman born in the 1980s is just under 5 feet 4 inches; her mother, born in the 1960s, is more than half an inch taller. Even her grandmother, born in the 1940s, is a bit taller. The average white woman born in the 1980s is about half an inch taller than her mother. . . . You have to go back to the antebellum South to find a similar shrinkage. The generation of white men born in the 1840s who experienced the ravages of the Civil War lost nearly an inch to their Northern counterparts. . . . the average height of adult Americans born from 1975 to 1986 has edged up again—with the exception of black women, whose height is moving in the opposite direction. . . .
Also baffling . . . is the disparity between black men and black women, "since they are subject to the same pre-birth conditions" and then grow up in the same environment.
"The only reasonable explanation we can come up with is diet and the obesity epidemic among [middle- and low-income] black women," said Komlos.
Over the last three decades, the prevalence of obesity among white Americans has tripled, while among blacks it has increased fivefold. . . . Almost 80 percent of black females are overweight or obese, compared with 62 percent of the total female population, according to the CDC. . . . Twenty-one percent of black females ages 2 to 19 are overweight or obese, compared with 12 percent of white girls.
Another oddity . . . is that black children, both male and female, grow faster and taller than their white counterparts in early childhood, but whites catch up and pass them during the teen years.
Pediatric growth experts offer one possible explanation. High caloric intake from an unhealthy diet fuels an early growth spurt among black children, plus it speeds the onset of puberty, especially for black girls, who now begin menstruating 8 1/2 months ahead of white girls. This early onset of puberty reduces the duration of the critical pre-adolescent growth spurt, resulting in a lower adult height.
28 December 2008
Black Women Getting Short, Fat, & Earlier Puberty
Progress sometimes takes a two steps forward, one step back trajectory.