To assess whether early modifiable dietary factors and obesity measures are associated with leukocyte telomere length at 3-5 years of age after controlling for the heritability of leukocyte telomere length in a prospective cohort of low-income Latina mothers and their children in San Francisco.

We analyzed data from the Latinx, Eating and Diabetes cohort, a prospective study of 97 woman-infant dyads. We used linear regression models to evaluate associations between early dietary factors and obesity measures and child leukocyte telomere length at 3-5 years of age. Multivariable models included child age at the time of telomere collection, breastfeeding at 6 months (yes/no), obesity at 6 months, maternal education, child sex, and maternal and paternal leukocyte telomere length.

Data for 73 of the 97 children at 3-5 years of age were analyzed. Any breastfeeding at 6 months was positively associated (β = 0.14; P = .02) and obesity at 6 months was negatively associated (β = −0.21; P < .001) with leukocyte telomere length in bivariate analyses. In multivariable models including parental leukocyte telomere length, obesity at 6 months was associated with a shorter leukocyte telomere length at 3-5 years of age (β = −0.15; P = .02). Analyses of dietary factors showed high flavored milk consumption at 3 years of age was associated with shorter leukocyte telomere length after adjustment for possible confounders.

In a low-income Latinx population, obesity at 6 months of age is negatively associated with cellular health at 3-5 years of age after controlling for genetic factors (parental leukocyte telomere length) associated with leukocyte telomere length. Early life obesity may be more deleterious for cellular health than obesity later in childhood.