Dr. Khursheed Navder, professor at the City University of New York School of Public Health and colleagues published their findings in Pediatric Obesity.
Their research aimed to assess whether ethnic differences in body fat are present at birth in healthy infants born at term, where body fat is measured using air displacement plethysmography and fat distribution by skin-fold thickness. Mothers of healthy newborns self-reported race. The main outcome measure was infant body fat at one to three days after birth, and covariates were age, birth weight, gestational age, and maternal pre-pregnancy weight. The researchers found that at birth African-American, Asian and Hispanic males, and African-American females have higher total fat mass than Caucasians. African-American, Asian, and Hispanic newborns have greater central fat deposition than do Caucasians. Although the significance of these findings is unclear, the authors noted that in adolescents and adults, greater central fat deposition is strongly associated with insulin resistance and type 2 diabetes.
The findings demonstrate that phenotyping of body composition traits beginning at birth requires sex and race/ethnicity specificity as a proxy for genetic ancestry. They suggest that the physiological processes that lead to disparities in obesity and related comorbidities might begin in utero.